312-50v13 Certified Ethical Hacker Exam (CEHv13) Questions and Answers

In CEH v13 Module 14: Cryptography, CAST-128 is defined as a symmetric block cipher based on a Feistel structure with:

Block size of 64 bits

12 or 16 rounds, depending on key size

Uses 8×32-bit S-boxes with complex structures (including bent functions)

Operates with modular addition/subtraction, XOR, key-dependent rotations, and masking keys (Km) and rotation keys (Kr)

All features described in the scenario match the CAST-128 algorithm.

Option Clarification:

B. AES: Operates on 128-bit blocks, uses Substitution-Permutation Network (SPN), not Feistel.

C. GOST: Russian block cipher, also Feistel-based, but structure and key use differ.

D. DES: Feistel cipher with 64-bit block size, but uses 16 rounds and simpler S-boxes.

Correct answer is A. CAST-128

An untethered jailbreak is one that allows a telephone to finish a boot cycle when being pwned with none interruption to jailbreak-oriented practicality.

Untethered jailbreaks area unit the foremost sought-after of all, however they’re additionally the foremost difficult to attain due to the powerful exploits and organic process talent they need. associate unbound jailbreak is sent over a physical USB cable association to a laptop or directly on the device itself by approach of associate application-based exploit, like a web site in campaign.

Upon running associate unbound jailbreak, you’ll be able to flip your pwned telephone off and on once more while not running the jailbreak tool once more. all of your jailbreak tweaks and apps would then continue in operation with none user intervention necessary.

It’s been an extended time since IOS has gotten the unbound jailbreak treatment. the foremost recent example was the computer-based Pangu break, that supported most handsets that ran IOS nine.1. We’ve additionally witnessed associate unbound jailbreak within the kind of JailbreakMe, that allowed users to pwn their handsets directly from the mobile campaign applications programme while not a laptop.

The ethical hacker conducted Test 1, which is a TCP/IP stack fingerprinting technique that uses the SYN and ECN-Echo flags to determine the OS of the target system. The SYN flag is used to initiate a TCP connection, and the ECN-Echo flag is used to indicate that the sender supports Explicit Congestion Notification (ECN), which is a mechanism to reduce network congestion. Different OSes have different implementations and responses to these flags, which can reveal their identity. For example, Windows XP and 2000 will reply with SYN and ECN-Echo flags set, while Linux will reply with only SYN flag set. By sending a TCP packet with these flags enabled to an open TCP port and observing the reply, the ethical hacker can probe the nature of the response and subsequently determine the OS fingerprint.

The ethical hacker adopted this specific approach because it is an advanced and stealthy technique that can evade some firewalls and intrusion detection systems (IDS) that may block or alert other types of packets, such as NULL, FIN, or Xmas packets. Moreover, this technique can provide more accurate and reliable results than other techniques, such as banner grabbing or passive analysis, that may depend on the availability or validity of the information provided by the target system.

The other options are not correct, as they describe different tests and reasons. Test 3 is a TCP/IP stack fingerprinting technique that uses the URG, PSH, SYN, and FIN flags to determine the OS of the target system. Test 2 is a TCP/IP stack fingerprinting technique that uses a NULL packet, which is a TCP packet with no flags enabled, to determine the OS of the target system. Test 6 is a TCP/IP stack fingerprinting technique that uses the ACK flag, which is used to acknowledge the receipt of a TCP segment, to determine the OS of the target system. References:

OS and Application Fingerprinting | SANS Institute

Operating System Fingerprinting | SpringerLink

OS and Application Fingerprinting - community.akamai.com

What is OS Fingerprinting and Techniques - Zerosuniverse

Comprehensive and Detailed Explanation:

IDS cannot easily detect malicious content in encrypted traffic. Since the payload is encrypted (e.g., HTTPS, SSL/TLS), it is unreadable without decryption.

Statement B is therefore FALSE.

From CEH v13 Courseware:

Module 13: IDS, Firewalls and Honeypots → Limitations of IDS

Once a suitable zombie has been found, performing a scan is easy. Simply specify the zombie hostname to the -sI option and Nmap does the rest. Example 5.19 shows an example of Ereet scanning the Recording Industry Association of America by bouncing an idle scan off an Adobe machine named Kiosk.

Example 5.19. An idle scan against the RIAA

# nmap -Pn -p- -sI kiosk.adobe.com www.riaa.com

Starting Nmap ( http://nmap.org )

Idlescan using zombie kiosk.adobe.com (192.150.13.111:80); Class: Incremental

Nmap scan report for 208.225.90.120

(The 65522 ports scanned but not shown below are in state: closed)

Port       State       Service

21/tcp     open        ftp

25/tcp     open        smtp

80/tcp     open        http

111/tcp    open        sunrpc

135/tcp    open        loc-srv

443/tcp    open        https

1027/tcp   open        IIS

1030/tcp   open        iad1

2306/tcp   open        unknown

5631/tcp   open        pcanywheredata

7937/tcp   open        unknown

7938/tcp   open        unknown

36890/tcp  open        unknown

Nmap done: 1 IP address (1 host up) scanned in 2594.47 seconds

Simple Network Management Protocol (SNMP) enumeration involves querying devices on the network for information such as routing tables, interface statistics, and system details.

Useful tools include:

A. SNMPUtil: A command-line Microsoft utility for sending SNMP requests.

B. SNScan: Tool from Foundstone for SNMP scanning and enumeration.

C. SNMPScan: Lightweight tool for scanning networks for SNMP-enabled devices.

D. SolarWinds IP Network Browser: A commercial tool for graphical SNMP enumeration.

From CEH v13 Courseware:

Module 4: Enumeration

Subsection: SNMP Enumeration Tools

Incorrect Option:

E. NMap can detect SNMP services, but is not specialized for SNMP enumeration like the others.

A man-in-the-middle attack using forged ICMP and ARP spoofing is a type of network-level session hijacking attack where an attacker inserts their machine into the communication between a client and a server, making it seem like the packets are flowing through the original path. This technique is primarily used to reroute the packets and intercept or modify the data exchanged between the client and the server.

A man-in-the-middle attack using forged ICMP and ARP spoofing works as follows1:

The attacker sends a forged ICMP redirect message to the client, claiming to be the gateway. The ICMP redirect message tells the client to use the attacker’s machine as the next hop for reaching the server’s network. The client updates its routing table accordingly and starts sending packets to the attacker’s machine instead of the gateway.

The attacker also sends a forged ARP reply message to the client, claiming to be the server. The ARP reply message associates the attacker’s MAC address with the server’s IP address. The client updates its ARP cache accordingly and starts sending packets to the attacker’s MAC address instead of the server’s MAC address.

The attacker receives the packets from the client and forwards them to the server, acting as a relay. The attacker can also monitor, modify, or drop the packets as they wish. The server responds to the packets and sends them back to the attacker, who then forwards them to the client. The client and the server are unaware of the attacker’s presence and think they are communicating directly with each other.

Therefore, Jake is studying a man-in-the-middle attack using forged ICMP and ARP spoofing, which is a type of network-level session hijacking attack.

A cloud carrier acts as an intermediary that provides connectivity and transport of cloud services between cloud consumers and cloud providers.

Cloud carriers provide access to consumers through network, telecommunication and other access devices. for instance, cloud consumers will obtain cloud services through network access devices, like computers, laptops, mobile phones, mobile web devices (MIDs), etc.

The distribution of cloud services is often provided by network and telecommunication carriers or a transport agent, wherever a transport agent refers to a business organization that provides physical transport of storage media like high-capacity hard drives.

Note that a cloud provider can started SLAs with a cloud carrier to provide services consistent with the level of SLAs offered to cloud consumers, and will require the cloud carrier to provide dedicated and secure connections between cloud consumers and cloud providers.

A DHCP starvation assault is a pernicious computerized assault that objectives DHCP workers. During a DHCP assault, an unfriendly entertainer floods a DHCP worker with false DISCOVER bundles until the DHCP worker debilitates its stock of IP addresses. When that occurs, the aggressor can deny genuine organization clients administration, or even stock an other DHCP association that prompts a Man-in-the-Middle (MITM) assault.

In a DHCP Starvation assault, a threatening entertainer sends a huge load of false DISCOVER parcels until the DHCP worker thinks they’ve used their accessible pool. Customers searching for IP tends to find that there are no IP addresses for them, and they’re refused assistance. Furthermore, they may search for an alternate DHCP worker, one which the unfriendly entertainer may give. What’s more, utilizing a threatening or sham IP address, that unfriendly entertainer would now be able to peruse all the traffic that customer sends and gets.

In an unfriendly climate, where we have a malevolent machine running some sort of an instrument like Yersinia, there could be a machine that sends DHCP DISCOVER bundles. This malevolent customer doesn’t send a modest bunch – it sends a great many vindictive DISCOVER bundles utilizing sham, made-up MAC addresses as the source MAC address for each solicitation.

In the event that the DHCP worker reacts to every one of these false DHCP DISCOVER parcels, the whole IP address pool could be exhausted, and that DHCP worker could trust it has no more IP delivers to bring to the table to legitimate DHCP demands.

When a DHCP worker has no more IP delivers to bring to the table, ordinarily the following thing to happen would be for the aggressor to get their own DHCP worker. This maverick DHCP worker at that point starts giving out IP addresses.

The advantage of that to the assailant is that if a false DHCP worker is distributing IP addresses, including default DNS and door data, customers who utilize those IP delivers and begin to utilize that default passage would now be able to be directed through the aggressor’s machine. That is all that an unfriendly entertainer requires to play out a man-in-the-center (MITM) assault.

The total data extracted by the attacker is E=xyz’u’, where x is the number of tables, y is the number of columns, z is the number of records, and u is the number of SQL payloads. To maximize E, the attacker would want to choose the highest values of z and u, while keeping x and y constant. Therefore, the situation where z=600 and u=2 would result in the highest extracted data volume, as E=42600*2=9600. The other situations would result in lower values of E, as shown below:

A: E=42400*4=12800

B: E=42550*2=8800

D: E=42500*3=12000

The attacker uses UNION SELECT statements to combine the results from different tables and columns, and DBMS_XSLPPOCESSOR.READ2CLOB to read sensitive files from the database server12. These techniques can bypass input validation and pattern matching measures that are based on the application’s responses3.

A honeypot may be a trap that an IT pro lays for a malicious hacker, hoping that they will interact with it during a way that gives useful intelligence. It’s one among the oldest security measures in IT, but beware: luring hackers onto your network, even on an isolated system, are often a dangerous game.

honeypot may be a good starting place: “A honeypot may be a computer or computing system intended to mimic likely targets of cyberattacks.” Often a honeypot are going to be deliberately configured with known vulnerabilities in situation to form a more tempting or obvious target for attackers. A honeypot won’t contain production data or participate in legitimate traffic on your network — that’s how you’ll tell anything happening within it’s a results of an attack. If someone’s stopping by, they’re up to no good.

That definition covers a various array of systems, from bare-bones virtual machines that only offer a couple of vulnerable systems to ornately constructed fake networks spanning multiple servers. and therefore the goals of these who build honeypots can vary widely also , starting from defense thorough to academic research. additionally , there’s now an entire marketing category of deception technology that, while not meeting the strict definition of a honeypot, is certainly within the same family. But we’ll get thereto during a moment.

honeypots aim to permit close analysis of how hackers do their dirty work. The team controlling the honeypot can watch the techniques hackers use to infiltrate systems, escalate privileges, and otherwise run amok through target networks. These sorts of honeypots are found out by security companies, academics, and government agencies looking to look at the threat landscape. Their creators could also be curious about learning what kind of attacks are out there, getting details on how specific sorts of attacks work, or maybe trying to lure a specific hackers within the hopes of tracing the attack back to its source. These systems are often inbuilt fully isolated lab environments, which ensures that any breaches don’t end in non-honeypot machines falling prey to attacks.

Production honeypots, on the opposite hand, are usually deployed in proximity to some organization’s production infrastructure, though measures are taken to isolate it the maximum amount as possible. These honeypots often serve both as bait to distract hackers who could also be trying to interrupt into that organization’s network, keeping them faraway from valuable data or services; they will also function a canary within the coalpit , indicating that attacks are underway and are a minimum of partially succeeding.

https://github.com/verovaleros/bluedriving

Bluedriving is a bluetooth wardriving utility. It can capture bluetooth devices, lookup their services, get GPS information and present everything in a nice web page. It can search for and show a lot of information about the device, the GPS address and the historic location of devices on a map. The main motivation of this tool is to research about the targeted surveillance of people by means of its cellular phone or car. With this tool you can capture information about bluetooth devices and show, on a map, the points where you have seen the same device in the past.

According to CEH v13 Module 04: Enumeration and Module 08: Sniffing, packet sniffers such as Wireshark, tcpdump, and EtherApe are designed to capture and analyze network traffic at the data link (Layer 2) and network (Layer 3) layers of the OSI model.

At Layer 2 (Data Link), sniffers capture Ethernet frames, including MAC addresses and frame type.

At Layer 3 (Network), sniffers interpret IP headers, IP addresses, and transport layer protocols (TCP, UDP).

They do not operate at Layer 1 (Physical) as they do not deal with raw electrical signals.

Packet sniffers also do not manipulate traffic but passively monitor and capture packets that traverse the network.

Therefore, the correct statement is:

Packet Sniffers operate on both Layer 2 & Layer 3 of the OSI model.

Option Analysis:

A. Layer 1: ❌ Incorrect. Layer 1 is the physical layer (electrical, optical signals).

B. Layer 2: ❌ Partially correct but incomplete.

C. Both Layer 2 & Layer 3: Correct. Full coverage of packet sniffing capabilities.

D. Layer 3: ❌ Partially correct but incomplete.

Reference from CEH v13 Courseware:

Module 08 – Sniffing, Section: How Packet Sniffers Work

CEH iLabs: Capturing Ethernet Frames and IP Packets Using Wireshark

OSI Model Mapping in CEH Official eBook

In CEH v13 Module 05: System Hacking, and in lab-based exploitation exercises, this is a classic fuzzer for buffer overflow testing.

The script creates increasingly larger strings of "A" (50, 100, 150...).

These are passed as arguments to different vulnerable commands on the target service (127.0.0.1:9999).

The goal is to trigger a crash, typically when input exceeds buffer limits (i.e., buffer overflow).

This is part of exploit development to identify the offset and locate the instruction pointer overwrite (EIP overwrite).

A brute force attack is a method of trying different combinations of passwords or keys to gain access to a system or service. It is not a reliable way of detecting a honeypot, as it may trigger an alert or response from the target. Moreover, a brute force attack does not provide any information about the system’s characteristics or behavior that could indicate a honeypot. A honeypot is a decoy system that is designed to attract and trap attackers, while providing security teams with valuable intelligence and insights. Therefore, an ethical hacker needs to use more subtle and stealthy techniques to detect and avoid honeypots.

The other options are valid techniques for detecting a honeypot. Probing system services and observing the three-way handshake can reveal anomalies or inconsistencies in the system’s responses, such as abnormal banners, ports, or protocols. Using honeypot detection tools like Send-Safe Honeypot Hunter can scan the target network and identify potential honeypots based on various criteria, such as IP address, domain name, or open ports. Analyzing the MAC address can detect instances running on VMware, which is a common platform for deploying honeypots. A honeypot running on VMware will have a MAC address that starts with 00:0C:29, 00:50:56, or 00:05:69. References:

What is a Honeypot? Types, Benefits, Risks and Best Practices

Using Honeypots for Network Intrusion Detection

Detecting Honeypot Access With Varonis

LAN Manager (LM) hashes are legacy password hashing methods used in older Windows systems (including Windows 2000 for backward compatibility). LM hashing works by:

Converting the password to uppercase.

Padding or truncating it to 14 characters.

Splitting it into two 7-character halves.

Using each half as a DES key to encrypt a known constant ("KGS!@#$%").

Therefore, LM hashing uses the DES (Data Encryption Standard) algorithm.

From CEH v13 Official Courseware:

Module 6: Malware Threats → Password Storage and LM Hash Structure

Bob wants Alice to verify that the message hasn’t been tampered with. This is a use case for ensuring data integrity and authenticity. The process described matches the creation of a digital signature:

Bob computes a checksum (typically a cryptographic hash) of the message.

Then, he encrypts this checksum (hash) using his own private key.

Alice receives the message and decrypts the checksum using Bob’s public key.

If the decrypted checksum matches the hash she computes from the received message, she confirms the message’s integrity and authenticity.

This is a fundamental principle of digital signatures.

Incorrect Options:

A. Alice's private key is never used by others; it's confidential.

B. Encrypting with Alice’s public key ensures confidentiality, not authenticity.

D. Bob’s public key is used by the receiver to verify authenticity, not for encryption in this context.

Reference – CEH v13 Official Courseware:

Module 20: Cryptography

Section: “Digital Signatures”

Subsection: “Using Private Keys to Sign and Public Keys to Verify”

CEH Engage Lab: Email Signing and Verification

===========

Comprehensive and Detailed Explanation:

The AAAA (Quad A) record is the DNS record type used to map a domain name to an IPv6 address. It is the IPv6 equivalent of an A (Address) record, which maps to an IPv4 address.

From CEH v13 Courseware:

Module 4: Enumeration → DNS Record Types

OS fingerprinting helps attackers identify the operating system and version running on a target host. This allows them to:

Determine potential vulnerabilities

Choose appropriate exploits for the OS version and configuration

Bypass ineffective defenses

From CEH v13 Courseware:

Module 3: Scanning Networks

Topic: Active and Passive OS Fingerprinting

CEH v13 Study Guide states:

“Fingerprinting identifies the OS type/version and helps attackers choose specific exploits that apply to that system.”

Incorrect Options:

A: Software enumeration is different from OS fingerprinting.

B/C: Misleading or incorrect in this context.

False Positives occur when a scanner, Web Application Firewall (WAF), or Intrusion Prevention System (IPS) flags a security vulnerability that you do not have. A false negative is the opposite of a false positive, telling you that you don't have a vulnerability when, in fact, you do.

A false positive is like a false alarm; your house alarm goes off, but there is no burglar. In web application security, a false positive is when a web application security scanner indicates that there is a vulnerability on your website, such as SQL Injection, when, in reality, there is not. Web security experts and penetration testers use automated web application security scanners to ease the penetration testing process. These tools help them ensure that all web application attack surfaces are correctly tested in a reasonable amount of time. But many false positives tend to break down this process. If the first 20 variants are false, the penetration tester assumes that all the others are false positives and ignore the rest. By doing so, there is a good chance that real web application vulnerabilities will be left undetected.

When checking for false positives, you want to ensure that they are indeed false. By nature, we humans tend to start ignoring false positives rather quickly. For example, suppose a web application security scanner detects 100 SQL Injection vulnerabilities. If the first 20 variants are false positives, the penetration tester assumes that all the others are false positives and ignore all the rest. By doing so, there are chances that real web application vulnerabilities are left undetected. This is why it is crucial to check every vulnerability and deal with each false positive separately to ensure false positives.

https://nmap.org/book/man-port-specification.html

NOTE: In my opinion, this is an absolutely wrong statement of the question. But you may come across a question with a similar wording on the exam. What does "fast" mean? If we want to increase the speed and intensity of the scan we can select the mode using the -T flag (0/1/2/3/4/5). At high -T values, we will sacrifice stealth and gain speed, but we will not limit functionality.

«nmap -T4 -F 10.10.0.0/24» This option is "correct" because of the -F flag.

-F (Fast (limited port) scan)

Specifies that you wish to scan fewer ports than the default. Normally Nmap scans the most common 1,000 ports for each scanned protocol. With -F, this is reduced to 100.

Technically, scanning will be faster, but just because we have reduced the number of ports by 10 times, we are just doing 10 times less work, not faster.

The AndroidManifest.xml file contains information of your package, including components of the appliance like activities, services, broadcast receivers, content providers etc.

It performs another tasks also:

• it’s responsible to guard the appliance to access any protected parts by providing the permissions.

• It also declares the android api that the appliance goes to use.

• It lists the instrumentation classes. The instrumentation classes provides profiling and other informations. These informations are removed just before the appliance is published etc.

This is the specified xml file for all the android application and located inside the basis directory.

STP prevents bridging loops in a redundant switched network environment. By avoiding loops, you can ensure that broadcast traffic does not become a traffic storm.

STP is a hierarchical tree-like topology with a “root” switch at the top. A switch is elected as root based on the lowest configured priority of any switch (0 through 65,535). When a switch boots up, it begins a process of identifying other switches and determining the root bridge. After a root bridge is elected, the topology is established from its perspective of the connectivity. The switches determine the path to the root bridge, and all redundant paths are blocked. STP sends configuration and topology change notifications and acknowledgments (TCN/TCA) using bridge protocol data units (BPDU).

An STP attack involves an attacker spoofing the root bridge in the topology. The attacker broadcasts out an STP configuration/topology change BPDU in an attempt to force an STP recalculation. The BPDU sent out announces that the attacker’s system has a lower bridge priority. The attacker can then see a variety of frames forwarded from other switches to it. STP recalculation may also cause a denial-of-service (DoS) condition on the network by causing an interruption of 30 to 45 seconds each time the root bridge changes. An attacker using STP network topology changes to force its host to be elected as the root bridge.

“Clearing tracks” is a post-exploitation phase in the ethical hacking methodology in which the attacker removes or alters system evidence to hide their activities and avoid detection. This may include:

Deleting or modifying event logs

Clearing bash history or command history

Removing malware traces

Disabling auditing

From CEH v13:

Corrupting or erasing event logs ensures that system administrators or forensic investigators cannot trace the intrusion or determine how the system was compromised.

Incorrect Options:

A. Creating a backdoor is part of the "Maintaining Access" phase, not "Clearing Tracks."

B. Injecting a rootkit is part of the "Gaining or Maintaining Access" stage.

C. Exploiting a vulnerability is part of the "Gaining Access" phase.

Reference – CEH v13 Official Courseware:

Module 05: System Hacking

Section: “Clearing Logs and Erasing Evidence”

Subsection: “Track-Clearing Techniques”

Lab: Log Manipulation and Covering Tracks

Active Online Attacks: Hash Injection/Pass-the-Hash (PtH) Attack A hash injection/PtH attack allows an attacker to inject a compromised hash into a local session and use the hash to validate network resources The attacker finds and extracts a logged-on domain admin account hash The attacker uses the extracted hash to log on to the domain controller

Worker Message Block (SMB) is an organization document sharing and information texture convention. SMB is utilized by billions of gadgets in a different arrangement of working frameworks, including Windows, MacOS, iOS , Linux, and Android. Customers use SMB to get to information on workers. This permits sharing of records, unified information the board, and brought down capacity limit needs for cell phones. Workers additionally use SMB as a feature of the Software-characterized Data Center for outstanding burdens like grouping and replication.

Since SMB is a far off record framework, it requires security from assaults where a Windows PC may be fooled into reaching a pernicious worker running inside a confided in organization or to a far off worker outside the organization edge. Firewall best practices and arrangements can upgrade security keeping malevolent traffic from leaving the PC or its organization.

For Windows customers and workers that don’t have SMB shares, you can obstruct all inbound SMB traffic utilizing the Windows Defender Firewall to keep far off associations from malignant or bargained gadgets. In the Windows Defender Firewall, this incorporates the accompanying inbound principles.

You should also create a new blocking rule to override any other inbound firewall rules. Use the following suggested settings for any Windows clients or servers that do not host SMB Shares:

Name: Block all inbound SMB 445

Description: Blocks all inbound SMB TCP 445 traffic. Not to be applied to domain controllers or computers that host SMB shares.

Action: Block the connection

Programs: All

Remote Computers: Any

Protocol Type: TCP

Local Port: 445

Remote Port: Any

Profiles: All

Scope (Local IP Address): Any

Scope (Remote IP Address): Any

Edge Traversal: Block edge traversal

You must not globally block inbound SMB traffic to domain controllers or file servers. However, you can restrict access to them from trusted IP ranges and devices to lower their attack surface. They should also be restricted to Domain or Private firewall profiles and not allow Guest/Public traffic.

In authentication, Multi-Factor Authentication (MFA) involves using more than one category of authentication factors:

Something you know (e.g., password)

Something you have (e.g., RFID badge, token)

Something you are (e.g., biometrics like fingerprints, facial recognition, gait)

In this scenario:

The RFID badge is "something you have" (a physical object).

The gait recognition (walking pattern) captured by the camera is a biometric—"something you are" (a physical characteristic).

Together, these two methods represent two distinct authentication factors, thereby implementing true multi-factor authentication.

Reference – CEH v13 Official Study Guide:

Module 5: System Hacking

Topic: Authentication Mechanisms

Quote:

“Examples of multi-factor authentication include combining biometrics (something you are) with a smart card or badge (something you have). Gait recognition is considered a behavioral biometric and falls under ‘something you are’.”

Incorrect Options Explained:

A. Incorrect — gait and RFID represent two separate factor types, not one.

C. No evidence in the scenario supports high false positives.

D. Gait analysis is a recognized biometric method and can be used for identification.

This phase having the hacker uses different techniques and tools to realize maximum data from the system. they’re –

• Password cracking – Methods like Bruteforce, dictionary attack, rule-based attack, rainbow table are used. Bruteforce is trying all combinations of the password. Dictionary attack is trying an inventory of meaningful words until the password matches. Rainbow table takes the hash value of the password and compares with pre-computed hash values until a match is discovered.

• Password attacks – Passive attacks like wire sniffing, replay attack. Active online attack like Trojans, keyloggers, hash injection, phishing. Offline attacks like pre-computed hash, distributed network and rainbow. Non electronic attack like shoulder surfing, social engineering and dumpster diving.

Comprehensive and Detailed Explanation:

Steganography allows someone to hide data (like a spreadsheet or document) within another innocuous-looking file (like an image, video, or audio). This disguises the presence of the data entirely, allowing it to bypass standard data loss prevention (DLP) systems and firewalls, which look for file types and suspicious patterns.

From CEH v13 Courseware:

Module 6: Malware Threats → Steganography and Covert Channels

https://www.eccouncil.org/what-is-social-engineering/

This Social Engineering scam involves an exchange of information that can benefit both the victim and the trickster. Scammers would make the prey believe that a fair exchange will be present between both sides, but in reality, only the fraudster stands to benefit, leaving the victim hanging on to nothing. An example of a Quid Pro Quo is a scammer pretending to be an IT support technician. The con artist asks for the login credentials of the company’s computer saying that the company is going to receive technical support in return. Once the victim has provided the credentials, the scammer now has control over the company’s computer and may possibly load malware or steal personal information that can be a motive to commit identity theft.

"A quid pro quo attack (aka something for something” attack) is a variant of baiting. Instead of baiting a target with the promise of a good, a quid pro quo attack promises a service or a benefit based on the execution of a specific action." https://resources.infosecinstitute.com/topic/common-social-engineering-attacks/#:~:text=A%20quid%20pro%20quo%20attack,execution%20of%20a%20specific%20action.

Banner grabbing is a technique wont to gain info about a computer system on a network and the services running on its open ports. administrators will use this to take inventory of the systems and services on their network. However, an to find will use banner grabbing so as to search out network hosts that are running versions of applications and operating systems with known exploits.

Some samples of service ports used for banner grabbing are those used by Hyper Text Transfer Protocol (HTTP), File Transfer Protocol (FTP), and Simple Mail Transfer Protocol (SMTP); ports 80, 21, and 25 severally. Tools normally used to perform banner grabbing are Telnet, nmap and Netcat.

For example, one may establish a connection to a target internet server using Netcat, then send an HTTP request. The response can usually contain info about the service running on the host:

This information may be used by an administrator to catalog this system, or by an intruder to narrow down a list of applicable exploits.

To prevent this, network administrators should restrict access to services on their networks and shut down unused or unnecessary services running on network hosts. Shodan is a search engine for banners grabbed from portscanning the Internet.

Appropriately controlling admittance to web content is significant for running a safe web worker. Index crossing or Path Traversal is a HTTP assault which permits aggressors to get to limited catalogs and execute orders outside of the web worker’s root registry.

Web workers give two primary degrees of security instruments

Access Control Lists (ACLs)

Root index

An Access Control List is utilized in the approval cycle. It is a rundown which the web worker’s manager uses to show which clients or gatherings can get to, change or execute specific records on the worker, just as other access rights.

The root registry is a particular index on the worker record framework in which the clients are kept. Clients can’t get to anything over this root.

For instance: the default root registry of IIS on Windows is C:\Inetpub\wwwroot and with this arrangement, a client doesn’t approach C:\Windows yet approaches C:\Inetpub\wwwroot\news and some other indexes and documents under the root catalog (given that the client is confirmed by means of the ACLs).

The root index keeps clients from getting to any documents on the worker, for example, C:\WINDOWS/system32/win.ini on Windows stages and the/and so on/passwd record on Linux/UNIX stages.

This weakness can exist either in the web worker programming itself or in the web application code.

To play out a registry crossing assault, all an assailant requires is an internet browser and some information on where to aimlessly discover any default documents and registries on the framework.

What an assailant can do if your site is defenseless

With a framework defenseless against index crossing, an aggressor can utilize this weakness to venture out of the root catalog and access different pieces of the record framework. This may enable the assailant to see confined documents, which could give the aggressor more data needed to additional trade off the framework.

Contingent upon how the site access is set up, the aggressor will execute orders by mimicking himself as the client which is related with “the site”. Along these lines everything relies upon what the site client has been offered admittance to in the framework.

Illustration of a Directory Traversal assault by means of web application code

In web applications with dynamic pages, input is generally gotten from programs through GET or POST solicitation techniques. Here is an illustration of a HTTP GET demand URL

GET http://test.webarticles.com/show.asp?view=oldarchive.html HTTP/1.1

Host: test.webarticles.com

With this URL, the browser requests the dynamic page show.asp from the server and with it also sends the parameter view with the value of oldarchive.html. When this request is executed on the web server, show.asp retrieves the file oldarchive.html from the server’s file system, renders it and then sends it back to the browser which displays it to the user. The attacker would assume that show.asp can retrieve files from the file system and sends the following custom URL.

GET http://test.webarticles.com/show.asp?view=../../../../../Windows/system.ini HTTP/1.1

Host: test.webarticles.com

This will cause the dynamic page to retrieve the file system.ini from the file system and display it to the user. The expression ../ instructs the system to go one directory up which is commonly used as an operating system directive. The attacker has to guess how many directories he has to go up to find the Windows folder on the system, but this is easily done by trial and error.

Example of a Directory Traversal attack via web server

Apart from vulnerabilities in the code, even the web server itself can be open to directory traversal attacks. The problem can either be incorporated into the web server software or inside some sample script files left available on the server.

The vulnerability has been fixed in the latest versions of web server software, but there are web servers online which are still using older versions of IIS and Apache which might be open to directory traversal attacks. Even though you might be using a web server software version that has fixed this vulnerability, you might still have some sensitive default script directories exposed which are well known to hackers.

For example, a URL request which makes use of the scripts directory of IIS to traverse directories and execute a command can be

GET http://server.com/scripts/..%5c../Windows/System32/cmd.exe?/c+dir+c:\ HTTP/1.1

Host: server.com

The request would return to the user a list of all files in the C:\ directory by executing the cmd.exe command shell file and run the command dir c:\ in the shell. The %5c expression that is in the URL request is a web server escape code which is used to represent normal characters. In this case %5c represents the character \.

Newer versions of modern web server software check for these escape codes and do not let them through. Some older versions however, do not filter out these codes in the root directory enforcer and will let the attackers execute such commands.

According to CEH v13 Module 08: Sniffing, the attack described is a classic example of ARP spoofing/poisoning which leads to Man-in-the-Middle (MITM) scenarios. In such attacks, a malicious actor sends forged ARP responses to associate their MAC address with the IP address of a target system, redirecting traffic through their machine.

Tool Used: BetterCAP

BetterCAP is a powerful, modular MITM framework.

It can:

Perform ARP spoofing

Intercept and manipulate HTTP/HTTPS traffic

Modify packets in real-time

Carry out credential harvesting and session hijacking

Miley's actions match the default behavior of BetterCAP during an ARP spoofing attack:

Spoof ARP to redirect traffic.

Intercept and analyze (or manipulate) traffic.

Option Clarification:

A. Gobbler: An older ARP tool, but mostly for ARP scanning, not modern MITM attacks.

B. KDerpNSpoof: Incorrect or misspelled; not a recognized CEH tool.

C. BetterCAP: Correct – used for ARP spoofing and traffic manipulation.

D. Wireshark: Passive sniffer; cannot perform ARP spoofing or MITM.

Wireless Threats - Confidentiality Attacks Launch of Wireless Attacks: Evil Twin Evil Twin is a wireless AP that pretends to be a legitimate AP by replicating another network name. Attackers set up a rogue AP outside the corporate perimeter and lures users to sign into the wrong AP. (P.2297/2281)

One of the most common Nmap usage scenarios is scanning an Ethernet LAN. Most LANs, especially those that use the private address range granted by RFC 1918, do not always use the overwhelming majority of IP addresses. When Nmap attempts to send a raw IP packet, such as an ICMP echo request, the OS must determine a destination hardware (ARP) address, such as the target IP, so that the Ethernet frame can be properly addressed. .. This is required to issue a series of ARP requests. This is best illustrated by an example where a ping scan is attempted against an Area Ethernet host. The –send-ip option tells Nmap to send IP-level packets (rather than raw Ethernet), even on area networks. The Wireshark output of the three ARP requests and their timing have been pasted into the session.

Raw IP ping scan example for offline targets

This example took quite a couple of seconds to finish because the (Linux) OS sent three ARP requests at 1 second intervals before abandoning the host. Waiting for a few seconds is excessive, as long as the ARP response usually arrives within a few milliseconds. Reducing this timeout period is not a priority for OS vendors, as the overwhelming majority of packets are sent to the host that actually exists. Nmap, on the other hand, needs to send packets to 16 million IP s given a target like 10.0.0.0/8. Many targets are pinged in parallel, but waiting 2 seconds each is very delayed.

There is another problem with raw IP ping scans on the LAN. If the destination host turns out to be unresponsive, as in the previous example, the source host usually adds an incomplete entry for that destination IP to the kernel ARP table. ARP tablespaces are finite and some operating systems become unresponsive when full. If Nmap is used in rawIP mode (–send-ip), Nmap may have to wait a few minutes for the ARP cache entry to expire before continuing host discovery.

ARP scans solve both problems by giving Nmap the highest priority. Nmap issues raw ARP requests and handles retransmissions and timeout periods in its sole discretion. The system ARP cache is bypassed. The example shows the difference. This ARP scan takes just over a tenth of the time it takes for an equivalent IP.

Example b ARP ping scan of offline target

In example b, neither the -PR option nor the -send-eth option has any effect. This is often because ARP has a default scan type on the Area Ethernet network when scanning Ethernet hosts that Nmap discovers. This includes traditional wired Ethernet as 802.11 wireless networks. As mentioned above, ARP scanning is not only more efficient, but also more accurate. Hosts frequently block IP-based ping packets, but usually cannot block ARP requests or responses and communicate over the network.Nmap uses ARP instead of all targets on equivalent targets, even if different ping types (such as -PE and -PS) are specified. LAN.. If you do not need to attempt an ARP scan at all, specify –send-ip as shown in Example a “Raw IP Ping Scan for Offline Targets”.

If you give Nmap control to send raw Ethernet frames, Nmap can also adjust the source MAC address. If you have the only PowerBook in your security conference room and a large ARP scan is initiated from an Apple-registered MAC address, your head may turn to you. Use the –spoof-mac option to spoof the MAC address as described in the MAC Address Spoofing section.

Social engineering is a non-technical attack that manipulates human behavior to gain access to systems or data. It often involves deception (e.g., phishing, pretexting, baiting) and requires no technical expertise or tools, making it a low-tech yet highly effective method.

Reference – CEH v13 Official Study Guide:

Module 9: Social Engineering

Quote:

“Social engineering exploits human psychology and trust to gain unauthorized access. It is considered a low-tech method because it does not require technical means.”

Incorrect Options Explained:

B. Eavesdropping may require technical tools to intercept data.

C. Scanning involves active use of tools to find vulnerabilities.

D. Sniffing is technical and requires tools to capture network traffic.

Syslog messages are typically sent over UDP or TCP port 514 to the Syslog server. In this case, Snort (192.168.0.99) should send alerts to Kiwi Syslog (192.168.0.150) using TCP/UDP port 514.

The correct Wireshark filter to check if Snort is sending the messages to the Syslog server is:

tcp.dstport==514 && ip.dst==192.168.0.150

Reference – CEH v13 Official Study Guide:

Module 8: Sniffing

Topic: Packet Sniffing and Analysis

Quote:

“Wireshark filters like tcp.dstport and ip.dst can be used to verify outbound logs and traffic from intrusion detection systems.”

Incorrect Options:

A & B: Use incorrect IP addresses or direction

C: Uses incorrect destination IP (should be the Syslog server)

===========

Tess King is attempting to gather all DNS records from a target zone. This process is referred to as a zone transfer (AXFR), which is typically performed by secondary name servers to synchronize DNS data with the primary. If improperly secured, attackers can initiate unauthorized zone transfers to enumerate valuable information such as:

Hostnames

IP addresses

Mail servers

Name servers

CEH v13 defines a zone transfer as a crucial step in DNS enumeration.

From CEH v13 Official Courseware:

Module 3: Scanning Networks

Topic: DNS Enumeration → Zone Transfers

CEH v13 Study Guide states:

“A zone transfer (AXFR) is a DNS transaction used to replicate DNS databases. Attackers can exploit this feature to extract all DNS information from an improperly secured server.”

Incorrect Options:

A. Zone harvesting is not a formal term.

C. Zone update refers to DNS dynamic update operations (e.g., DDNS).

D. Zone estimate is not a DNS-related process.

Twofish is an encryption algorithm designed by Bruce Schneier. It’s a symmetric key block cipher with a block size of 128 bits, with keys up to 256 bits. it’s associated with AES (Advanced Encryption Standard) and an earlier block cipher called Blowfish. Twofish was actually a finalist to become the industry standard for encryption, but was ultimately beaten out by the present AES.

Twofish has some distinctive features that set it aside from most other cryptographic protocols. For one, it uses pre-computed, key-dependent S-boxes. An S-box (substitution-box) may be a basic component of any symmetric key algorithm which performs substitution. within the context of Twofish’s block cipher, the S-box works to obscure the connection of the key to the ciphertext. Twofish uses a pre-computed, key-dependent S-box which suggests that the S-box is already provided, but depends on the cipher key to decrypt the knowledge .

How Secure is Twofish?

Twofish is seen as a really secure option as far as encryption protocols go. one among the explanations that it wasn’t selected because the advanced encryption standard is thanks to its slower speed. Any encryption standard that uses a 128-bit or higher key, is theoretically safe from brute force attacks. Twofish is during this category.

Because Twofish uses “pre-computed key-dependent S-boxes”, it are often susceptible to side channel attacks. this is often thanks to the tables being pre-computed. However, making these tables key-dependent helps mitigate that risk. There are a couple of attacks on Twofish, but consistent with its creator, Bruce Schneier, it didn’t constitute a real cryptanalysis. These attacks didn’t constitue a practical break within the cipher.

Products That Use Twofish

GnuPG: GnuPG may be a complete and free implementation of the OpenPGP standard as defined by RFC4880 (also referred to as PGP). GnuPG allows you to encrypt and sign your data and communications; it features a flexible key management system, along side access modules for all types of public key directories.

KeePass: KeePass may be a password management tool that generates passwords with top-notch security. It’s a free, open source, lightweight and easy-to-use password manager with many extensions and plugins.

Password Safe: Password Safe uses one master password to stay all of your passwords protected, almost like the functionality of most of the password managers on this list. It allows you to store all of your passwords during a single password database, or multiple databases for various purposes. Creating a database is straightforward , just create the database, set your master password.

PGP (Pretty Good Privacy): PGP is employed mostly for email encryption, it encrypts the content of the e-mail . However, Pretty Good Privacy doesn’t encrypt the topic and sender of the e-mail , so make certain to never put sensitive information in these fields when using PGP.

TrueCrypt: TrueCrypt may be a software program that encrypts and protects files on your devices. With TrueCrypt the encryption is transparent to the user and is completed locally at the user’s computer. this suggests you’ll store a TrueCrypt file on a server and TrueCrypt will encrypt that file before it’s sent over the network.

Passive sniffing refers to listening to or capturing network traffic without sending any packets or altering the communication stream. The attacker’s system operates in "promiscuous mode" to monitor all traffic flowing through the network segment. This technique is mostly used in environments like hub-based or unencrypted Wi-Fi networks, where traffic is visible to all systems.

According to the CEH v13 Official Courseware, Module 08: Sniffing, under the subsection "Passive Sniffing", the following capabilities are associated with passive sniffing:

Capturing unencrypted credentials (usernames and passwords)

Identifying protocols, services, IP addresses, and hostnames

Monitoring HTTP sessions, cookies, and other clear-text traffic

Gathering detailed information for fingerprinting and enumeration

Exporting traffic to PCAPs for forensic and offline analysis

However, passive sniffing does not involve any active interference with the traffic. Therefore, actions like “modifying and replaying” packets require an attacker to craft and inject packets into the network — this is considered active sniffing or traffic manipulation, which is out of scope for passive techniques.

Thus:

Option A: Valid for passive sniffing (host discovery via captured traffic)

Option B: Invalid for passive sniffing (requires active traffic manipulation)

Option C: Valid (if data is unencrypted)

Option D: Valid (captures traffic for offline review)

Reference – CEH v13 Official Courseware:

Module 08: Sniffing

Section: “Passive Sniffing vs Active Sniffing”

Study Guide Pages: Usually found under “Types of Sniffing Techniques”

CEH iLabs/Engage Scenarios: Packet capture and Wireshark lab modules

https://support.riverbed.com/content/support/software/steelcentral-npm/airpcap.html

Since this question refers specifically to analyzing a wireless network, it is obvious that we need an option with AirPcap (Riverbed AirPcap USB-based adapters capture 802.11 wireless traffic for analysis). Since it works with two traffic analyzers SteelCentral Packet Analyzer (Cascade Pilot) or Wireshark, the correct option would be "Wireshark with Airpcap."

NOTE: AirPcap adapters no longer available for sale effective January 1, 2018, but a question on this topic may occur on your exam.

===========

The protocol that you would recommend to the team to achieve the secure exchange of the symmetric key is the Diffie-Hellman protocol. The Diffie-Hellman protocol is a key agreement protocol that allows two or more parties to establish a shared secret key over an unsecured communication channel, without having to exchange the key itself. The Diffie-Hellman protocol works as follows12:

The parties agree on a large prime number p and a generator g, which are public parameters that can be known by anyone.

Each party chooses a random private number a or b, which are kept secret from anyone else.

Each party computes a public value A or B, by raising g to the power of a or b modulo p, i.e., A = g^a mod p and B = g^b mod p.

Each party sends their public value A or B to the other party over the unsecured channel.

Each party computes the shared secret key K, by raising the received public value to the power of their own private number modulo p, i.e., K = A^b mod p = B^a mod p.

The parties can now use the shared secret key K to encrypt and decrypt the data using a symmetric key encryption algorithm, such as AES or 3DES.

The Diffie-Hellman protocol can ensure the secure exchange of the symmetric key because it relies on the mathematical difficulty of computing discrete logarithms, which means that it is hard to find the private numbers a or b given the public values A or B, g, and p. Therefore, an attacker who intercepts the public values A or B cannot easily compute the shared secret key K, and thus cannot decrypt the data encrypted with K12.

The other options are not as appropriate as option B for the following reasons:

A. Implementing SSL certificates on your company’s web servers: This option is not relevant because SSL certificates are not used to exchange symmetric keys, but to authenticate the identity of the web servers and to establish a secure connection using public key encryption. SSL certificates are digital certificates that contain the public key and the identity information of the web server, and are issued and signed by a trusted certificate authority (CA). When a client connects to a web server, the web server sends its SSL certificate to the client, who verifies it with the CA. If the verification is successful, the client and the web server use the public key in the certificate to exchange a symmetric key, which is then used to encrypt and decrypt the data. However, this option does not address the scenario of transmitting data over an unsecured communication channel, which may not involve web servers or SSL certificates34.

C. Switching all data transmission to the HTTPS protocol: This option is not sufficient because HTTPS protocol is not a protocol for exchanging symmetric keys, but a protocol for securing web traffic using SSL or TLS encryption. HTTPS protocol is a combination of HTTP protocol and SSL or TLS protocol, which means that it uses HTTP for the application layer communication and SSL or TLS for the transport layer encryption. When a client requests a web page from a web server using HTTPS protocol, the client and the web server establish a secure connection using SSL or TLS protocol, which involves the exchange of SSL certificates and a symmetric key, as explained in option A. Then, the client and the web server use the symmetric key to encrypt and decrypt the HTTP data. However, this option does not address the scenario of transmitting data over an unsecured communication channel, which may not involve web servers or HTTPS protocol5 .

D. Utilizing SSH for secure remote logins to the servers: This option is not applicable because SSH is not a protocol for exchanging symmetric keys, but a protocol for securing remote access to servers using public key authentication and encryption. SSH is a protocol that allows a client to securely connect to a server and execute commands or transfer files over an encrypted channel. SSH uses public key cryptography to authenticate the identity of the server and the client, and to exchange a symmetric key, which is then used to encrypt and decrypt the data. However, this option does not address the scenario of transmitting data over an unsecured communication channel, which may not involve remote logins or SSH protocol .

WS-Security (Web Services Security) is a protocol specification that provides a means for securing SOAP-based messages. It defines how to add authentication, encryption, and digital signatures to SOAP headers, helping ensure message integrity and confidentiality.

According to CEH v13 Official Courseware:

WS-Security is an extension of SOAP.

It supports features such as:

Authentication via tokens (e.g., username, X.509)

Message integrity via digital signatures

Message confidentiality via XML encryption

Incorrect Options:

A. WSDL (Web Services Description Language) describes the web service interface but does not provide security.

B. WS Work Processes is not a defined web service security standard.

C. WS-Policy allows expressing security requirements, but enforcement is handled by WS-Security.

Reference – CEH v13 Official Courseware:

Module 14: Hacking Web Applications

Section: "Web Services Security"

Subsection: "WS-* Standards"

===========

https://blog.mailfence.com/how-do-digital-signatures-work/

https://en.wikipedia.org/wiki/Digital_signature

A digital signature is a mathematical technique used to validate the authenticity and integrity of a message, software, or digital document. It's the digital equivalent of a handwritten signature or stamped seal, but it offers far more inherent security. A digital signature is intended to solve the problem of tampering and impersonation in digital communications.

Digital signatures can provide evidence of origin, identity, and status of electronic documents, transactions, or digital messages. Signers can also use them to acknowledge informed consent.

Digital signatures are based on public-key cryptography, also known as asymmetric cryptography. Two keys are generated using a public key algorithm, such as RSA (Rivest-Shamir-Adleman), creating a mathematically linked pair of keys, one private and one public.

Digital signatures work through public-key cryptography's two mutually authenticating cryptographic keys. The individual who creates the digital signature uses a private key to encrypt signature-related data, while the only way to decrypt that data is with the signer's public key.

A Boot Sector Virus infects the master boot record (MBR) of the system. When a system boots, it first loads the MBR into memory. A Boot Sector Virus takes advantage of this by moving the original MBR to a different location on the hard disk and writing itself to the original MBR location. This ensures that it is executed first during system startup.

As per CEH v13 course material:

“A boot sector virus infects the master boot record of a hard disk. It moves the original boot sector to a different location on the hard disk and replaces it with its own malicious code. When the computer is booted, the virus loads first and then hands control to the original boot sector code.”

Reference – CEH v13 Study Guide:

Module 06: Malware Threats, Section: “Types of Malware”, Subsection: “Boot Sector Viruses”

Incorrect Options Explained:

A: Describes directory virus behavior, not boot sector.

B: The virus moves MBR on the hard disk, not RAM.

D: Some viruses overwrite MBR, but most preserve the original and move it to another disk location to maintain system operability.

Comprehensive and Detailed Explanation From CEH v13 Guide:

The Network Time Protocol (NTP) is used by systems, including Linux servers, to synchronize their clocks with a time server. If NTP fails, time discrepancies may lead to inaccurate log records and affect security monitoring.

CEH v13 Reference:

Module 17: Evading IDS, Firewalls, and Honeypots – Log Tampering

“Accurate timekeeping is essential for proper logging and correlation. NTP ensures system time is synchronized across hosts.”

=============================================================

1. AV (Asset value) = $300 + (14 * $10) = $440 - the cost of a hard drive plus the work of a recovery person, i.e.how much would it take to replace 1 asset? 10 hours for resorting the OS and soft + 4 hours for DB restore multiplies by hourly rate of the recovery person.

2. SLE (Single Loss Expectancy) = AV * EF (Exposure Factor) = $440 * 1 = $440

3. ARO (Annual rate of occurrence) = 1/3 (every three years, meaning the probability of occurring during 1 years is 1/3)

4. ALE (Annual Loss Expectancy) = SLE * ARO = 0.33 * $440 = $145.2

https://en.wikipedia.org/wiki/RADIUS

Remote Authentication Dial-In User Service (RADIUS) is a networking protocol that provides centralized authentication, authorization, and accounting (AAA) management for users who connect and use a network service.

RADIUS is a client/server protocol that runs in the application layer, and can use either TCP or UDP. Network access servers, which control access to a network, usually contain a RADIUS client component that communicates with the RADIUS server. RADIUS is often the back-end of choice for 802.1X authentication. A RADIUS server is usually a background process running on UNIX or Microsoft Windows.

Authentication and authorization

The user or machine sends a request to a Network Access Server (NAS) to gain access to a particular network resource using access credentials. The credentials are passed to the NAS device via the link-layer protocol—for example, Point-to-Point Protocol (PPP) in the case of many dialup or DSL providers or posted in an HTTPS secure web form.

In turn, the NAS sends a RADIUS Access Request message to the RADIUS server, requesting authorization to grant access via the RADIUS protocol.

This request includes access credentials, typically in the form of username and password or security certificate provided by the user. Additionally, the request may contain other information which the NAS knows about the user, such as its network address or phone number, and information regarding the user's physical point of attachment to the NAS.

The RADIUS server checks that the information is correct using authentication schemes such as PAP, CHAP or EAP. The user's proof of identification is verified, along with, optionally, other information related to the request, such as the user's network address or phone number, account status, and specific network service access privileges. Historically, RADIUS servers checked the user's information against a locally stored flat-file database. Modern RADIUS servers can do this or can refer to external sources—commonly SQL, Kerberos, LDAP, or Active Directory servers—to verify the user's credentials.

The RADIUS server then returns one of three responses to the NAS:

1) Access-Reject,

2) Access-Challenge,

3) Access-Accept.

Access-Reject

The user is unconditionally denied access to all requested network resources. Reasons may include failure to provide proof of identification or an unknown or inactive user account.

Access-Challenge

Requests additional information from the user such as a secondary password, PIN, token, or card. Access-Challenge is also used in more complex authentication dialogs where a secure tunnel is established between the user machine and the Radius Server in a way that the access credentials are hidden from the NAS.

Access-Accept

The user is granted access. Once the user is authenticated, the RADIUS server will often check that the user is authorized to use the network service requested. A given user may be allowed to use a company's wireless network, but not its VPN service, for example. Again, this information may be stored locally on the RADIUS server or may be looked up in an external source such as LDAP or Active Directory.

The given rule syntax is consistent with Snort, a popular open-source Intrusion Detection System (IDS). This rule alerts when any TCP traffic from any source IP and port is sent to IPs within the 192.168.100.0/24 subnet on port 21 (FTP), triggering the alert message: “FTP on the network!”

The Snort rule format is:

alert protocol source_IP source_port -> destination_IP destination_port (rule_options)

CEH v13 course materials teach this rule format under IDS/IPS configuration.

From CEH v13 Guide:

“Snort rules are used in IDS/IPS to define suspicious traffic patterns. An example rule: alert tcp any any -> 192.168.1.0/24 21 (msg: 'FTP detected') triggers an alert on FTP traffic within a subnet.”

Incorrect Options:

A/C. IP tables are used in firewalls and routers but follow a completely different syntax.

B. FTP servers do not use such alerting rules.

Reference – CEH v13 Study Guide:

Module 12: Evading IDS, Firewalls, and Honeypots

Section: Snort IDS Configuration

===========

While perimeter defenses like firewalls and IPS provide a layer of protection, internal systems (such as network elements) must also be hardened. This includes:

Enforcing strong authentication

Applying regular patches and updates

Conducting vulnerability assessments and security audits

Security should be layered (defense in depth), and reliance on perimeter defense alone is insufficient.

Reference – CEH v13 Official Study Guide:

Module 3: Scanning Networks / Module 18: Incident Response

Quote:

“Internal systems must be hardened with secure configurations and tested regularly. A layered security approach is required even in protected environments.”

Incorrect Options:

B & C. Relying only on perimeter or physical security is not sufficient

D. While backup sites are part of DR, they don’t replace proactive protection

===========

A white hat (or a white hat hacker) is an ethical computer hacker, or a computer security expert, who focuses on penetration testing and in other testing methodologies that ensures the safety of an organization’s information systems. Ethical hacking may be a term meant to imply a broader category than simply penetration testing. Contrasted with black hat, a malicious hacker, the name comes from Western films, where heroic and antagonistic cowboys might traditionally wear a white and a black hat respectively. While a white hat hacker hacks under good intentions with permission, and a black hat hacker, most frequently unauthorized, has malicious intent, there’s a 3rd kind referred to as a gray hat hacker who hacks with good intentions but sometimes without permission.

White hat hackers can also add teams called “sneakers and/or hacker clubs”,red teams, or tiger teams.

While penetration testing concentrates on attacking software and computer systems from the beginning – scanning ports, examining known defects in protocols and applications running on the system and patch installations, as an example – ethical hacking may include other things. A full-blown ethical hack might include emailing staff to invite password details, searching through executive’s dustbins and typically breaking and entering, without the knowledge and consent of the targets. Only the owners, CEOs and Board Members (stake holders) who asked for such a censoring of this magnitude are aware. to undertake to duplicate a number of the destructive techniques a true attack might employ, ethical hackers may arrange for cloned test systems, or organize a hack late in the dark while systems are less critical. In most up-to-date cases these hacks perpetuate for the long-term con (days, if not weeks, of long-term human infiltration into an organization). Some examples include leaving USB/flash key drives with hidden auto-start software during a public area as if someone lost the tiny drive and an unsuspecting employee found it and took it.

Some other methods of completing these include:

• DoS attacks

• Social engineering tactics

• Reverse engineering

• Network security

• Disk and memory forensics

• Vulnerability research

• Security scanners such as:

– W3af

– Nessus

– Burp suite

• Frameworks such as:

– Metasploit

• Training Platforms

These methods identify and exploit known security vulnerabilities and plan to evade security to realize entry into secured areas. they’re ready to do that by hiding software and system ‘back-doors’ which will be used as a link to information or access that a non-ethical hacker, also referred to as ‘black-hat’ or ‘grey-hat’, might want to succeed in .

https://en.wikipedia.org/wiki/MAC_filtering

MAC filtering is a security method based on access control. Each address is assigned a 48-bit address, which is used to determine whether we can access a network or not. It helps in listing a set of allowed devices that you need on your Wi-Fi and the list of denied devices that you don’t want on your Wi-Fi. It helps in preventing unwanted access to the network. In a way, we can blacklist or white list certain computers based on their MAC address. We can configure the filter to allow connection only to those devices included in the white list. White lists provide greater security than blacklists because the router grants access only to selected devices.

It is used on enterprise wireless networks having multiple access points to prevent clients from communicating with each other. The access point can be configured only to allow clients to talk to the default gateway, but not other wireless clients. It increases the efficiency of access to a network.

The router allows configuring a list of allowed MAC addresses in its web interface, allowing you to choose which devices can connect to your network. The router has several functions designed to improve the network's security, but not all are useful. Media access control may seem advantageous, but there are certain flaws.

On a wireless network, the device with the proper credentials such as SSID and password can authenticate with the router and join the network, which gets an IP address and access to the internet and any shared resources.

MAC address filtering adds an extra layer of security that checks the device’s MAC address against a list of agreed addresses. If the client’s address matches one on the router’s list, access is granted; otherwise, it doesn’t join the network.

Incident Handling and Response Incident handling and response (IH&R) is the process of taking organized and careful steps when reacting to a security incident or cyberattack. Steps involved in the IH&R process: 3.Incident Triage - The IH&R team further analyzes the compromised device to find incident details such as the type of attack, its severity, target, impact, and method of propagation, and any vulnerabilities it exploited. (P.84/68)

Error-based SQL Injection is a type of in-band SQL Injection attack that relies on error messages thrown by the database server to obtain information about the structure of the database. In some cases, error-based SQL injection alone is enough for an attacker to enumerate an entire database.

The ethical hacker is likely to use this type of SQL Injection attack because the application responds to logically incorrect queries with detailed error messages that divulge the underlying database’s structure. This means that the attacker can craft malicious SQL queries that trigger errors and reveal information such as table names, column names, data types, etc. The attacker can then use this information to construct more complex queries that extract data from the database.

For example, if the application uses the following query to display the username of a user based on the user ID:

SELECT username FROM users WHERE id = '$id'

The attacker can inject a single quote at the end of the user ID parameter to cause a syntax error:

SELECT username FROM users WHERE id = '1'

The application might display an error message like this:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''1'' at line 1

This error message reveals that the database server is MySQL and that the user ID parameter is enclosed in single quotes. The attacker can then use other techniques such as UNION, subqueries, or conditional statements to manipulate the query and retrieve data from other tables or columns.

SOX stands for Sarbanes-Oxley Act of 2002. It is a U.S. federal law enacted to protect shareholders and the general public from accounting errors and corporate fraud.

Key points:

Requires strict internal controls and financial disclosures in publicly traded companies.

Mandates regular audits and IT security controls related to financial data.

Applies especially to accounting systems, databases, access controls, and IT procedures related to financial reporting.

Incorrect Options:

A. PCI-DSS relates to securing credit card data.

B. FISMA pertains to federal agency cybersecurity standards.

D. ISO/IEC 27001:2013 is an international information security standard, not a legal requirement for financial integrity.

Reference – CEH v13 Official Courseware:

Module 01: Introduction to Ethical Hacking

Section: “Compliance and Legal Concepts”

Table: "Major Laws and Regulations in Information Security"

===========

The hacker could have used the technique of manipulating white spaces in SQL queries to bypass signature detection. This technique involves inserting, removing, or replacing white spaces in SQL queries with other characters or symbols that are either ignored or interpreted as white spaces by the SQL engine, but not by the signature-based IDS. This way, the hacker can alter the appearance of the query and evade the pattern matching of the IDS, while preserving the functionality and logic of the query. For example, the hacker could replace the space character with a tab character, a newline character, a comment symbol, or a URL-encoded value, such as %2012.

The other options are not correct for the following reasons:

A. Utilizing the char encoding function to convert hexadecimal and decimal values into characters that pass-through SQL engine parsing: This option is not feasible because the char encoding function is not supported by all SQL engines, and it may not be able to convert all hexadecimal and decimal values into valid characters. Moreover, the char encoding function may not be able to bypass the signature detection of the IDS, as it may still match the keywords or syntax of the SQL query3.

B. Using the URL encoding method to replace characters with their ASCII codes in hexadecimal form: This option is not effective because the URL encoding method is not applicable to SQL queries, as it is designed for encoding special characters in URLs. The URL encoding method may not be able to replace all characters with their ASCII codes, and it may not be able to preserve the functionality and logic of the SQL query. Furthermore, the URL encoding method may not be able to evade the signature detection of the IDS, as it may still match the keywords or syntax of the SQL query4.

C. Implementing sophisticated matches such as “OR ‘john’ = john" in place of classical matches like “OR 1-1”: This option is not advanced because it is a common and basic SQL injection technique that does not involve any evasion or obfuscation. This technique involves injecting a logical expression that is always true, such as “OR ‘john’ = john” or “OR 1-1”, to bypass the authentication or authorization checks of the SQL query. However, this technique may not be able to bypass the signature detection of the IDS, as it may easily match the keywords or syntax of the SQL query.

DNS tunneling may be a method wont to send data over the DNS protocol, a protocol which has never been intended for data transfer. due to that, people tend to overlook it and it’s become a well-liked but effective tool in many attacks.

Most popular use case for DNS tunneling is obtaining free internet through bypassing captive portals at airports, hotels, or if you are feeling patient the not-so-cheap on the wing Wi-Fi.

On those shared internet hotspots HTTP traffic is blocked until a username/password is provided, however DNS traffic is usually still allowed within the background: we will encode our HTTP traffic over DNS and voilà, we’ve internet access.

This sounds fun but reality is, browsing anything on DNS tunneling is slow. Like, back to 1998 slow.

Another more dangerous use of DNS tunneling would be bypassing network security devices (Firewalls, DLP appliances…) to line up an immediate and unmonitored communications channel on an organisation’s network. Possibilities here are endless: Data exfiltration, fixing another penetration testing tool… you name it.

To make it even more worrying, there’s an outsized amount of easy to use DNS tunneling tools out there.

There’s even a minimum of one VPN over DNS protocol provider (warning: the planning of the web site is hideous, making me doubt on the legitimacy of it).

As a pentester all this is often great, as a network admin not such a lot .

How does it work:

For those that ignoramus about DNS protocol but still made it here, i feel you deserve a really brief explanation on what DNS does: DNS is sort of a phonebook for the web , it translates URLs (human-friendly language, the person’s name), into an IP address (machine-friendly language, the phone number). That helps us remember many websites, same as we will remember many people’s names.

For those that know what DNS is i might suggest looking here for a fast refresh on DNS protocol, but briefly what you would like to understand is:

• A Record: Maps a website name to an IP address.

example.com ? 12.34.52.67

• NS Record (a.k.a. Nameserver record): Maps a website name to an inventory of DNS servers, just in case our website is hosted in multiple servers.

example.com ? server1.example.com, server2.example.com

Who is involved in DNS tunneling?

• Client. Will launch DNS requests with data in them to a website .

• One Domain that we will configure. So DNS servers will redirect its requests to an outlined server of our own.

• Server. this is often the defined nameserver which can ultimately receive the DNS requests.

The 6 Steps in DNS tunneling (simplified):

1. The client encodes data during a DNS request. The way it does this is often by prepending a bit of knowledge within the domain of the request. for instance : mypieceofdata.server1.example.com

2. The DNS request goes bent a DNS server.

3. The DNS server finds out the A register of your domain with the IP address of your server.

4. The request for mypieceofdata.server1.example.com is forwarded to the server.

5. The server processes regardless of the mypieceofdata was alleged to do. Let’s assume it had been an HTTP request.

6. The server replies back over DNS and woop woop, we’ve got signal.

Bypassing Firewalls through the DNS Tunneling Method DNS operates using UDP, and it has a 255-byte limit on outbound queries. Moreover, it allows only alphanumeric characters and hyphens. Such small size constraints on external queries allow DNS to be used as an ideal choice to perform data exfiltration by various malicious entities. Since corrupt or malicious data can be secretly embedded into the DNS protocol packets, even DNSSEC cannot detect the abnormality in DNS tunneling. It is effectively used by malware to bypass the firewall to maintain communication between the victim machine and the C&C server. Tools such as NSTX (https://sourceforge.net), Heyoka (http://heyoka.sourceforge.netuse), and Iodine (https://code.kryo.se) use this technique of tunneling traffic across DNS port 53. CEH v11 Module 12 Page 994

https://en.wikipedia.org/wiki/Subnetwork

This is a fairly simple question. You must to understand what a subnet mask is and how it works.

A subnetwork or subnet is a logical subdivision of an IP network.The practice of dividing a network into two or more networks is called subnetting.

Computers that belong to the same subnet are addressed with an identical most-significant bit-group in their IP addresses. This results in the logical division of an IP address into two fields: the network number or routing prefix and the rest field or host identifier. The rest field is an identifier for a specific host or network interface.

The routing prefix may be expressed in Classless Inter-Domain Routing (CIDR) notation written as the first address of a network, followed by a slash character (/), and ending with the bit-length of the prefix. For example, 198.51.100.0/24 is the prefix of the Internet Protocol version 4 network starting at the given address, having 24 bits allocated for the network prefix, and the remaining 8 bits reserved for host addressing. Addresses in the range 198.51.100.0 to 198.51.100.255 belong to this network. The IPv6 address specification 2001:db8::/32 is a large address block with 296 addresses, having a 32-bit routing prefix.

For IPv4, a network may also be characterized by its subnet mask or netmask, which is the bitmask that when applied by a bitwise AND operation to any IP address in the network, yields the routing prefix. Subnet masks are also expressed in dot-decimal notation like an address. For example, 255.255.255.0 is the subnet mask for the prefix 198.51.100.0/24.

In CEH v13 Module 11: Hacking Wireless Networks, WPA3 is presented as the latest Wi-Fi security protocol, and it includes:

Simultaneous Authentication of Equals (SAE) protocol — a more secure key exchange mechanism.

Replaces WPA2's Pre-Shared Key (PSK) method to prevent dictionary and key recovery attacks.

SAE (a.k.a. Dragonfly) prevents attackers from capturing handshakes for offline cracking.

Option Clarification:

A. WEP: Obsolete and weak.

B. WPA: Early improvement over WEP, still vulnerable.

C. WPA2: Uses PSK and vulnerable to key reinstallation attacks (KRACK).

D. WPA3: Correct – uses SAE/Dragonfly, resistant to known attacks.

Nmap provides a scripting engine (NSE) that includes a script named http-methods. This script sends OPTIONS requests to the web server to determine which HTTP methods are supported. Identifying risky methods like PUT and DELETE helps detect misconfigured or vulnerable web servers.

Example command:

nmap --script http-methods -p 80

Reference – CEH v13 Official Study Guide:

Module 11: Hacking Web Applications

Quote:

“The Nmap script http-methods helps identify enabled HTTP methods including potentially dangerous ones like PUT and DELETE.”

Incorrect Options Explained:

B. http-enum is used to enumerate directories and applications, not methods.

C. http-headers retrieves HTTP headers.

D. http-git checks for Git repositories on web servers.

===========

The network is using an uncrackable encryption method, which makes it difficult to crack the Wi-Fi password. WPA2 Personal with AES encryption is the strongest form of security offered by Wi-Fi devices at the moment, and it should be used for all purposes. AES stands for Advanced Encryption Standard, and it is a symmetric-key algorithm that uses a 128-bit, 192-bit, or 256-bit key to encrypt and decrypt data. AES is considered to be uncrackable by brute force attacks, as it would take an impractical amount of time and computational power to try all possible key combinations12. Therefore, unless you have access to the Wi-Fi password or the encryption key, you will not be able to decrypt the network traffic and crack the password.

The other options are not correct for the following reasons:

A. The Wi-Fi password is too complex and long: This option is not relevant because the Wi-Fi password is not directly used to encrypt the network traffic. Instead, the password is used to generate a Pre-Shared Key (PSK), which is then used to derive a Pairwise Master Key (PMK), which is then used to derive a Pairwise Transient Key (PTK), which is then used to encrypt the data. Therefore, the complexity and length of the password do not affect the encryption strength, as long as the password is not easily guessed or leaked34.

B. Your hacking tool is outdated: This option is not plausible because even if your hacking tool is outdated, it would not affect your ability to capture the network traffic and attempt to crack the password. The hacking tool may not support the latest Wi-Fi standards or protocols, but it should still be able to capture the raw data packets and save them in a file. The cracking process would depend on the encryption algorithm and the key, not on the hacking tool.

D. The network is using MAC address filtering: This option is not feasible because MAC address filtering is a technique that restricts network access and communication to trusted devices based on their MAC addresses, which are unique identifiers assigned to network interfaces. MAC address filtering can prevent unauthorized devices from joining the network, but it cannot prevent authorized devices from capturing the network traffic. Moreover, MAC address filtering can be easily bypassed by spoofing the MAC address of an allowed device56.

Scammers often impersonate legitimate organizations using free email services like @yahoo.com. "Yahoo Bank" is not a legitimate institution, and a real financial entity would use an official domain (e.g., @yahoobank.com). This is a textbook phishing/smishing attempt.

Reference – CEH v13 Official Study Guide:

Module 9: Social Engineering

Quote:

“Attackers often use free email services and impersonate authority figures to trick users. Always verify the sender’s domain and context.”

Incorrect Options:

B. Irrelevant—legitimate people may be unknown too.

C. Responding increases risk.

D. It is not from a verified organization.

===========

Snort is an open-source Network Intrusion Detection and Prevention System (NIDS/NIPS) capable of real-time traffic analysis and packet logging. It functions as a sniffer and can detect various forms of attacks using signature-based rules.

CEH v13 Reference:

Module 10: Evading IDS, Firewalls, and Honeypots

"Snort can operate as a sniffer, logger, or full NIDS capable of real-time traffic analysis."

━━━━━━━━━━━━━━━━━━━━━━

This is a classic phishing scam — a form of social engineering used to trick victims into giving up sensitive information.

Statement D is incorrect because:

Antivirus, anti-spyware, and firewalls are primarily designed to stop malware and network intrusions.

They cannot reliably detect social engineering attacks like phishing emails, especially if the email content appears legitimate.

Detection of phishing is more reliant on user awareness and email filtering policies.

From CEH v13 Courseware:

Module 7: Social Engineering

Module 5: Email Security

CEH v13 Study Guide states:

“Phishing attacks are psychological rather than purely technical. Antivirus tools cannot detect or prevent all phishing attempts because these are based on user manipulation rather than system compromise.”

Zigbee could be a wireless technology developed as associate open international normal to deal with the unique desires of affordable, low-power wireless IoT networks. The Zigbee normal operates on the IEEE 802.15.4 physical radio specification and operates in unauthorised bands as well as a pair of.4 GHz, 900 MHz and 868 MHz.

The 802.15.4 specification upon that the Zigbee stack operates gained confirmation by the Institute of Electrical and physical science Engineers (IEEE) in 2003. The specification could be a packet-based radio protocol supposed for affordable, battery-operated devices. The protocol permits devices to speak in an exceedingly kind of network topologies and may have battery life lasting many years.

The Zigbee three.0 Protocol

The Zigbee protocol has been created and ratified by member corporations of the Zigbee Alliance.Over three hundred leading semiconductor makers, technology corporations, OEMs and repair corporations comprise the Zigbee Alliance membership. The Zigbee protocol was designed to supply associate easy-to-use wireless information answer characterised by secure, reliable wireless network architectures.

THE ZIGBEE ADVANTAGE

The Zigbee 3.0 protocol is intended to speak information through rip-roaring RF environments that area unit common in business and industrial applications. Version 3.0 builds on the prevailing Zigbee normal however unifies the market-specific application profiles to permit all devices to be wirelessly connected within the same network, no matter their market designation and performance. what is more, a Zigbee 3.0 certification theme ensures the ability of product from completely different makers. Connecting Zigbee three.0 networks to the information science domain unveil observance and management from devices like smartphones and tablets on a local area network or WAN, as well as the web, and brings verity net of Things to fruition.

Zigbee protocol options include:

Support for multiple network topologies like point-to-point, point-to-multipoint and mesh networks

Low duty cycle – provides long battery life

Low latency

Direct Sequence unfold Spectrum (DSSS)

Up to 65,000 nodes per network

128-bit AES encryption for secure information connections

Collision avoidance, retries and acknowledgements

This is another short-range communication protocol based on the IEEE 203.15.4 standard. Zig-Bee is used in devices that transfer data infrequently at a low rate in a restricted area and within a range of 10–100 m.

Webhooks are one of a few ways internet applications will communicate with one another.

It allows you to send real-time data from one application to another whenever a given event happens.

For example, let’s say you’ve created an application using the Foursquare API that tracks when people check into your restaurant. You ideally wish to be able to greet customers by name and provide a complimentary drink when they check in.

What a webhook will is notify you any time someone checks in, therefore you’d be able to run any processes that you simply had in your application once this event is triggered.

The data is then sent over the web from the application wherever the event originally occurred, to the receiving application that handles the data.

Here’s a visual representation of what that looks like:

A webhook url is provided by the receiving application, and acts as a phone number that the other application will call once an event happens.

Only it’s more complicated than a phone number, because data about the event is shipped to the webhook url in either JSON or XML format. this is known as the “payload.”

Here’s an example of what a webhook url looks like with the payload it’s carrying:

What are Webhooks? Webhooks are user-defined HTTP callback or push APIs that are raised based on events triggered, such as comment received on a post and pushing code to the registry. A webhook allows an application to update other applications with the latest information. Once invoked, it supplies data to the other applications, which means that users instantly receive real-time information. Webhooks are sometimes called “Reverse APIs” as they provide what is required for API specification, and the developer should create an API to use a webhook. A webhook is an API concept that is also used to send text messages and notifications to mobile numbers or email addresses from an application when a specific event is triggered. For instance, if you search for something in the online store and the required item is out of stock, you click on the “Notify me” bar to get an alert from the application when that item is available for purchase. These notifications from the applications are usually sent through webhooks.

In CEH v13 Module 05: System Hacking, and Module 14: Access Control, Identity Management, and Cryptography, Single Sign-On (SSO) is defined as a system that allows users to authenticate once and gain access to multiple systems without re-entering credentials.

SSO uses a Central Authentication Server (CAS).

Common technologies: Kerberos, OAuth, SAML, AD Federation Services.

Improves user convenience and centralized credential management.

https://www.darknet.org.uk/2017/07/bluto-dns-recon-zone-transfer-brute-forcer/

"Attackers also use DNS lookup tools such as DNSdumpster.com, Bluto, and Domain Dossier to retrieve DNS records for a specified domain or hostname. These tools retrieve information such as domains and IP addresses, domain Whois records, DNS records, and network Whois records." CEH Module 02 Page 138

A hybrid attack is a method that combines the dictionary attack with brute-force techniques. It starts with a list of known words (like in a dictionary attack) and then mutates them by:

Appending or prepending numbers (e.g., password1, 123hello)

Adding special characters (e.g., P@ssword!, admin#123)

Varying letter casing or leetspeak (e.g., h@x0r)

From CEH v13 Courseware:

Module 6: Malware Threats → Password Cracking Methods

Incorrect Options:

B: Linear is not a password cracking method.

C: Symmetric refers to encryption, not password cracking.

D: Brute-force tries every possible combination but does not start with a word list.

The described method is a classic example of a Side-Channel Attack, specifically a Timing Attack.

Key characteristics:

It exploits variations in response time from a system to infer sensitive information, such as the correct number of characters in a password.

In this scenario, if a correct character causes a longer processing time, the attacker can deduce the correct sequence iteratively.

According to CEH v13:

Side-channel attacks do not directly break encryption but rely on observing system behavior like timing, power consumption, or electromagnetic leaks.

These attacks are effective against poorly implemented authentication mechanisms or embedded systems like ICS/SCADA.

Incorrect Options:

B. Denial-of-service is aimed at making systems unavailable, not extracting credentials.

C. HMI-based attacks involve manipulating the human-machine interface of ICS systems.

D. Buffer overflow exploits memory handling flaws, not timing behavior.

Reference – CEH v13 Official Courseware:

Module 20: Cryptography

Section: “Cryptanalysis and Side-Channel Attacks”

Subsection: “Timing Attacks and Password Recovery”

A Kerberoasting attack is a technique that exploits the Kerberos authentication protocol to obtain the password hash of a service account that has a Service Principal Name (SPN). An attacker can request a service ticket (TGS) for the SPN using a valid user’s ticket (TGT) and then attempt to crack the password hash offline. To prevent the attacker from using the TGS to access the service, the system administrator should invalidate the TGS as soon as possible. This can be done by changing the password of the service account, which will generate a new password hash and render the old TGS useless. Alternatively, the system administrator can use tools like Mimikatz to purge the TGS from the memory of the domain controller or the client system. Performing a system reboot, deleting the compromised user’s account, or changing the NTLM password hash used to encrypt the ST are not effective ways to invalidate the TGS, as they do not affect the encryption of the TGS or the validity of the TGT. References:

EC-Council CEHv12 Courseware Module 11: Hacking Webservers, page 11-24

What is a Kerberoasting Attack? – CrowdStrike

How to Perform Kerberoasting Attacks: The Ultimate Guide - StationX

Cross-Site Request Forgery (CSRF) is covered in CEH v13 Module 12: Hacking Web Applications. It occurs when an attacker tricks a victim’s browser into making unintended, authenticated requests to a web application where the victim is already logged in.

Example:

User logs in to a banking site.

While logged in, the attacker sends the user a crafted link that submits a transaction via a hidden request.

Since the user’s session cookies are valid, the bank processes the request.

Why Other Options Are Incorrect:

A. Session hijacking: Steals session tokens but doesn’t involve forcing browser actions.

B. SSRF: Server sends a request to an internal service, not via user's browser.

D. XSS: Executes scripts in the user’s browser but doesn't force HTTP requests under the user’s identity.

In CEH v13 Module 09: Social Engineering, spear-phishing is described as a targeted email-based attack in which malicious actors craft highly personalized emails to specific individuals within an organization.

Characteristics from the scenario:

The attacker sends a fraudulent email to an employee.

The email contains a malicious attachment.

Once opened, malware is installed, targeting ICS/SCADA components.

The attack spreads and ultimately damages industrial systems.

This is a classic spear-phishing attack used as the initial infection vector in Advanced Persistent Threats (APT) targeting industrial control systems.

Why Others Are Incorrect:

B. SMiShing: SMS-based phishing; not email-related.

C. Reconnaissance: Pre-attack information gathering, not execution.

D. HMI-based attack: Targets Human-Machine Interface devices, but that’s not how the attack started here.

HTTP cookies may store authentication tokens, allowing users to remain logged in. If a browser retains cookies after closing, an attacker with access to the device could hijack active sessions.

Automatically deleting cookies upon termination reduces the window of opportunity for session hijacking.

Reference – CEH v13 Official Study Guide:

Module 11: Hacking Web Applications

Topic: Session Management

Quote:

“Session hijacking exploits persistent cookies or session IDs stored in browsers. Enforcing cookie deletion helps prevent this attack.”

Incorrect Options:

A. SQL databases are unrelated to browser cookies.

C. Browser cookies don’t store OS-level passwords.

D. This may be a secondary concern, but not the primary mitigation.

===========

STARTTLS is an SMTP command that allows the client to upgrade an existing insecure connection to a secure, encrypted TLS connection. It is widely supported by SMTP servers and used to protect email transmissions from interception.

Reference – CEH v13 Official Study Guide:

Module 20: Cryptography

Section: Secure Email Communication

Quote:

“STARTTLS is an SMTP command used to initiate encryption on an existing plaintext connection using TLS.”

Incorrect Options:

A. Opportunistic TLS is a concept, not a command

B & C. UPGRADETLS and FORCETLS are not valid SMTP commands

<03>

Windows Messenger administration

Courier administration is an organization based framework notice Windows administration by Microsoft that was remembered for some prior forms of Microsoft Windows.

This resigned innovation, despite the fact that it has a comparable name, isn’t connected in any capacity to the later, Internet-based Microsoft Messenger administration for texting or to Windows Messenger and Windows Live Messenger (earlier named MSN Messenger) customer programming.

The Messenger Service was initially intended for use by framework managers to tell Windows clients about their networks.[1] It has been utilized malevolently to introduce spring up commercials to clients over the Internet (by utilizing mass-informing frameworks which sent an ideal message to a predetermined scope of IP addresses). Despite the fact that Windows XP incorporates a firewall, it isn’t empowered naturally. Along these lines, numerous clients got such messages. Because of this maltreatment, the Messenger Service has been debilitated as a matter of course in Windows XP Service Pack 2.

An anomaly-based intrusion detection system is an intrusion detection system for detecting both network and computer intrusions and misuse by monitoring system activity and classifying it as either normal or anomalous. The classification is based on heuristics or rules, rather than patterns or signatures, and attempts to detect any type of misuse that falls out of normal system operation. This is as opposed to signature-based systems, which can only detect attacks for which a signature has previously been created.

In order to positively identify attack traffic, the system must be taught to recognize normal system activity. The two phases of a majority of anomaly detection systems consist of the training phase (where a profile of normal behaviors is built) and the testing phase (where current traffic is compared with the profile created in the training phase). Anomalies are detected in several ways, most often with artificial intelligence type techniques. Systems using artificial neural networks have been used to great effect. Another method is to define what normal usage of the system comprises using a strict mathematical model, and flag any deviation from this as an attack. This is known as strict anomaly detection.[3] Other techniques used to detect anomalies include data mining methods, grammar-based methods, and the Artificial Immune System.

Network-based anomalous intrusion detection systems often provide a second line of defense to detect anomalous traffic at the physical and network layers after it has passed through a firewall or other security appliance on the border of a network. Host-based anomalous intrusion detection systems are one of the last layers of defense and reside on computer endpoints. They allow for fine-tuned, granular protection of endpoints at the application level.

Anomaly-based Intrusion Detection at both the network and host levels have a few shortcomings; namely a high false-positive rate and the ability to be fooled by a correctly delivered attack. Attempts have been made to address these issues through techniques used by PAYL and MCPAD.

Launching Fileless Malware through Phishing Attackers commonly use social engineering techniques such as phishing to spread fileless malware to the target systems. Fileless malware exploits vulnerabilities in system tools to load and run malicious payloads on the victim’s machine to compromise the sensitive information stored in the process memory. (P.978/962)

Using default settings on a web server is considered a security risk because it can reveal the server software type and version, which can help attackers identify potential vulnerabilities and launch targeted attacks. For example, if the default settings include a server signature that displays the name and version of the web server software, such as Apache 2.4.46, an attacker can search for known exploits or bugs that affect that specific software and version. Additionally, default settings may also include other insecure configurations, such as weak passwords, unnecessary services, or open ports, that can expose the web server to unauthorized access or compromise.

The best initial step to mitigate this risk is to change the default settings to hide or obscure the server software type and version, as well as to disable or remove any unnecessary or insecure features. For example, to hide the server signature, one can modify the ServerTokens and ServerSignature directives in the Apache configuration file1. Alternatively, one can use a web application firewall or a reverse proxy to mask the server information from the client requests2. Changing the default settings can reduce the attack surface and make it harder for attackers to exploit the web server.

One may append the comment “–” operator along with the String for the username and whole avoid executing the password segment of the SQL query. Everything when the — operator would be considered as comment and not dead.

To launch such an attack, the value passed for name could be ’OR ‘1’=‘1’ ; —

Statement = “SELECT * FROM ‘CustomerDB’ WHERE ‘name’ = ‘ ”+ userName + “ ‘ AND ‘password’ = ‘ ” + passwd + “ ‘ ; ”

Statement = “SELECT * FROM ‘CustomerDB’ WHERE ‘name’ = ‘ ’ OR ‘1’=‘1‘;– + “ ‘ AND ‘password’ = ‘ ” + passwd + “ ‘ ; ”

All the records from the customer database would be listed.

Yet, another variation of the SQL Injection Attack can be conducted in dbms systems that allow multiple SQL injection statements. Here, we will also create use of the vulnerability in sure dbms whereby a user provided field isn’t strongly used in or isn’t checked for sort constraints.

This could take place once a numeric field is to be employed in a SQL statement; but, the programmer makes no checks to validate that the user supplied input is numeric.

Variation is an evasion technique whereby the attacker can easily evade any comparison statement. The attacker does this by placing characters such as “' or '1'='1'” in any basic injection statement such as “or 1=1” or with other accepted SQL comments.

Evasion Technique: Variation Variation is an evasion technique whereby the attacker can easily evade any comparison statement. The attacker does this by placing characters such as “' or '1'='1'” in any basic injection statement such as “or 1=1” or with other accepted SQL comments. The SQL interprets this as a comparison between two strings or characters instead of two numeric values. As the evaluation of two strings yields a true statement, similarly, the evaluation of two numeric values yields a true statement, thus rendering the evaluation of the complete query unaffected. It is also possible to write many other signatures; thus, there are infinite possibilities of variation as well. The main aim of the attacker is to have a WHERE statement that is always evaluated as “true” so that any mathematical or string comparison can be used, where the SQL can perform the same.

Dynamic ARP inspection (DAI) protects switching devices against Address Resolution Protocol (ARP) packet spoofing (also known as ARP poisoning or ARP cache poisoning).

DAI inspects ARPs on the LAN and uses the information in the DHCP snooping database on the switch to validate ARP packets and to protect against ARP spoofing. ARP requests and replies are compared against entries in the DHCP snooping database, and filtering decisions are made based on the results of those comparisons. When an attacker tries to use a forged ARP packet to spoof an address, the switch compares the address with entries in the database. If the media access control (MAC) address or IP address in the ARP packet does not match a valid entry in the DHCP snooping database, the packet is dropped.

Bluesnarfing is the unauthorized access of information from a wireless device through a Bluetooth connection, often between phones, desktops, laptops, and PDAs (personal digital assistant).

The SSID (service set identifier) is the name of your wireless network. SSID broadcast is how your router transmits this name to surrounding devices. Its primary function is to make your network visible and easily accessible. Most routers broadcast their SSIDs automatically. To disable or enable SSID broadcast, you need to change your router’s settings.

Disabling SSID broadcast will make your Wi-FI network name invisible to other users. However, this only hides the name, not the network itself. You cannot disguise the router's activity, so hackers can still attack it.

With your network invisible to wireless devices, connecting becomes a bit more complicated. Just giving a Wi-FI password to your guests is no longer enough. They have to configure their settings manually by including the network name, security mode, and other relevant info.

Disabling SSID might be a small step towards online security, but by no means should it be your final one. Before considering it as a security measure, consider the following aspects:

- Disabling SSID broadcast will not hide your network completely

Disabling SSID broadcast only hides the network name, not the fact that it exists. Your router constantly transmits so-called beacon frames to announce the presence of a wireless network. They contain essential information about the network and help the device connect.

- Third-party software can easily trace a hidden network

Programs such as NetStumbler or Kismet can easily locate hidden networks. You can try using them yourself to see how easy it is to find available networks – hidden or not.

- You might attract unwanted attention.

Disabling your SSID broadcast could also raise suspicion. Most of us assume that when somebody hides something, they have a reason to do so. Thus, some hackers might be attracted to your network.

In CEH v13 Module 03: Scanning Networks, under the Nmap Host Discovery Techniques, TCP SYN ping scan is explained as one of the methods used to determine whether a host is online by sending SYN packets to specified TCP ports.

When using Nmap:

-PS specifies a TCP SYN ping scan. It sends SYN packets to a given port (by default port 80, unless specified) to check whether a host is up and whether the port is open.

The response type to this SYN packet determines the host status:

If a SYN/ACK is received, it indicates the port is open, and the host is up.

If RST is received, the port is closed, but the host is still considered online.

If no response or ICMP unreachable is received, the host may be down or filtered.

Clarification of options:

A. -pp: This is not a valid Nmap option.

B. -PO: This sends IP Protocol Ping, used less frequently and not the same as SYN ping.

C. -PS: Correct. Performs a TCP SYN Ping Scan.

D. -PA: Sends TCP ACK Ping, used to determine firewall presence but not the same as SYN scan.

Reference from CEH v13 Study Guide and Course Material:

CEH v13 Official Module 03 – Scanning Networks, Slide: Nmap Host Discovery Techniques

EC-Council iLabs - Scanning Networks Practical Lab Guide: Section on nmap -sn -PS

Nmap Official Documentation (also referenced in CEH): https://nmap.org/book/man-host-discovery.html

These types of attacks occur when faults or glitches are INJECTED into the Power supply that can be used for remote execution.

SSL/TLS is a protocol that provides encryption and authentication for data in transit between a client and a server. However, SSL/TLS does not provide any protection against data tampering, which is the alteration, deletion, or insertion of data without authorization or proper validation. Data tampering can compromise the integrity and accuracy of the data, and potentially lead to breaches or fraud. To detect and prevent data tampering, you should implement IPsec in addition to SSL/TLS. IPsec is a protocol that provides encryption, authentication, and integrity for data in transit at the network layer. IPsec uses cryptographic mechanisms, such as digital signatures and hash-based message authentication codes (HMACs), to verify the identity of the sender and the receiver, and to ensure that the data has not been modified during transmission. IPsec can also provide replay protection, which prevents an attacker from retransmitting old or duplicate packets. By combining SSL/TLS and IPsec, you can achieve a higher level of security and reliability for your cloud-based application. References:

EC-Council CEHv12 Courseware Module 18: Cryptography, page 18-20

EC-Council CEHv12 Courseware Module 19: Cloud Computing, page 19-29

A comprehensive guide to data tampering

Tamper Detection

Ettercap is a comprehensive MITM attack tool that supports live traffic interception and content injection. It can modify HTTP streams in real time and inject malicious payloads, such as JavaScript or applets, into web traffic.

Reference – CEH v13 Official Study Guide:

Module 8: Sniffing

Quote:

“Ettercap allows attackers to intercept, analyze, and alter data on the fly, including injecting malicious content like Java applets in HTTP sessions during MITM attacks.”

Incorrect Options Explained:

A & D. Wireshark and Tcpdump are passive sniffers with no injection capability.

C. Aircrack-ng is for Wi-Fi key cracking, not traffic manipulation.

===========

https://en.wikipedia.org/wiki/Residual_risk

The residual risk is the risk or danger of an action or an event, a method or a (technical) process that, although being abreast with science, still conceives these dangers, even if all theoretically possible safety measures would be applied (scientifically conceivable measures); in other words, the amount of risk left over after natural or inherent risks have been reduced by risk controls.

· Residual risk = (Inherent risk) – (impact of risk controls)

A vulnerability assessment is a systematic review of security weaknesses in an information system. It evaluates if the system is susceptible to any known vulnerabilities, assigns severity levels to those vulnerabilities, and recommends remediation or mitigation, if and whenever needed1. A vulnerability assessment can be performed using various tools and techniques, depending on the scope and objectives of the assessment.

Considering the potential vulnerability sources, the best initial approach to vulnerability assessment is to check for hardware and software misconfigurations to identify any possible loopholes. Hardware and software misconfigurations are common sources of vulnerabilities that can expose the system to unauthorized access, data breaches, or service disruptions. Hardware and software misconfigurations can include:

Insecure default settings, such as weak passwords, open ports, unnecessary services, or verbose error messages.

Improper access control policies, such as granting excessive privileges, allowing anonymous access, or failing to revoke access for terminated users.

Lack of encryption or authentication mechanisms, such as using plain text protocols, storing sensitive data in clear text, or transmitting data without verifying the identity of the sender or receiver.

Outdated or incompatible software versions, such as using unsupported or deprecated software, failing to apply security patches, or having software conflicts or dependencies.

Checking for hardware and software misconfigurations can help identify any possible loopholes that could be exploited by attackers to compromise the system or the data. Checking for hardware and software misconfigurations can be done using various tools, such as:

Configuration management tools, such as Ansible, Puppet, or Chef, that can automate the deployment and maintenance of consistent and secure configurations across the system.

Configuration auditing tools, such as Nipper, Lynis, or OpenSCAP, that can scan the system for deviations from the desired or expected configurations and report any issues or vulnerabilities.

Configuration testing tools, such as Inspec, Serverspec, or Testinfra, that can verify the system’s compliance with the specified configuration rules and standards.

Therefore, checking for hardware and software misconfigurations is the best initial approach to vulnerability assessment, as it can help identify and eliminate any possible loopholes that could pose a security risk to the system or the data.

A Stealth or Tunneling Virus is designed specifically to evade detection by antivirus software and system monitoring tools. These viruses work by intercepting and modifying the operating system’s service call interrupts (such as INT 13h and INT 21h in DOS systems), which are used to access files or system services.

By hooking into these interrupts, the virus can return clean or forged data to antivirus scanners, thus hiding its malicious presence from detection tools.

Tunneling viruses may also operate at a lower level to evade even more advanced antivirus detection methods, making them particularly dangerous and hard to detect.

Reference – CEH v13 Official Study Guide:

Module 6: Malware Threats

Section: Types of Viruses

Quote:

“Tunneling viruses attempt to avoid detection by antivirus programs by installing themselves in the interrupt handler chain. These viruses intercept operating system calls to conceal their activities.”

Incorrect Options Explained:

A. Macro viruses target applications like Microsoft Word/Excel and use embedded macros, but do not alter service call interrupts.

C. Cavity viruses insert code into empty spaces in files without changing the file size but do not modify interrupts.

D. Polymorphic viruses mutate their code to avoid signature-based detection but do not typically interfere with system interrupts directly.

https://en.wikipedia.org/wiki/Network_Time_Protocol

The Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks.

NTP is intended to synchronize all participating computers within a few milliseconds of Coordinated Universal Time (UTC). It uses the intersection algorithm, a modified version of Marzullo's algorithm, to select accurate time servers and is designed to mitigate variable network latency effects. NTP can usually maintain time to within tens of milliseconds over the public Internet and achieve better than one millisecond accuracy in local area networks. Asymmetric routes and network congestion can cause errors of 100 ms or more.

The protocol is usually described in terms of a client-server model but can easily be used in peer-to-peer relationships where both peers consider the other to be a potential time source. Implementations send and receive timestamps using the User Datagram Protocol (UDP) on port number 123.

In LM hashing (used in legacy Windows systems), passwords are split into two 7-character chunks. If a password is fewer than 8 characters, the second half is padded with nulls and hashed to a constant value.

That constant is:

AAD3B435B51404EE

Thus, the second half of the LM hash (the rightmost 16 characters) is always the same if the password is < 8 characters.

From CEH v13 Courseware:

Module 6: Malware Threats → LM Hash Characteristics

CEH v13 Study Guide states:

“If the password is less than 8 characters, the second half of the LM hash will always be ‘AAD3B435B51404EE’, indicating the hash belongs to a short password.”

Two-factor Authentication or 2FA is a user identity verification method, where two of the three possible authentication factors are combined to grant access to a website or application.1) something the user knows, 2) something the user has, or 3) something the user is.

The possible factors of authentication are:

· Something the User Knows:

This is often a password, passphrase, PIN, or secret question. To satisfy this authentication challenge, the user must provide information that matches the answers previously provided to the organization by that user, such as “Name the town in which you were born.”

· Something the User Has:

This involves entering a one-time password generated by a hardware authenticator. Users carry around an authentication device that will generate a one-time password on command. Users then authenticate by providing this code to the organization. Today, many organizations offer software authenticators that can be installed on the user’s mobile device.

· Something the User Is:

This third authentication factor requires the user to authenticate using biometric data. This can include fingerprint scans, facial scans, behavioral biometrics, and more.

For example: In internet security, the most used factors of authentication are:

something the user has (e.g., a bank card) and something the user knows (e.g., a PIN code). This is two-factor authentication. Two-factor authentication is also sometimes referred to as strong authentication, Two-Step Verification, or 2FA.

The key difference between Multi-Factor Authentication (MFA) and Two-Factor Authentication (2FA) is that, as the term implies, Two-Factor Authentication utilizes a combination of two out of three possible authentication factors. In contrast, Multi-Factor Authentication could utilize two or more of these authentication factors.

In order to circumvent network protection tools, cybercriminals may forge a TCP session more efficiently by submitting a bogus SYN packet, a series of ACK packets, and at least one RST (reset) or FIN (connection termination) packet. This tactic allows crooks to get around defenses that only keep tabs on incoming traffic rather than analyzing return traffic.

WS-Address provides additional routing information in the SOAP header to support asynchronous communication. This technique allows the transmission of web service requests and response messages using different TCP connections

https://www.google.com/search?client=firefox-b-d &q=WS-Address+spoofing

CEH V11 Module 14 Page 1896

In CEH v13 Module 14: Cryptography, IPSec (Internet Protocol Security) is defined as a framework used to establish secure communication channels over IP networks, particularly in VPNs.

IPSec supports encryption, authentication, and integrity.

Operates in Tunnel Mode (VPNs) or Transport Mode (End-to-End).

Core protocols: AH (Authentication Header) and ESP (Encapsulating Security Payload).

Option Analysis:

A. PEM: Privacy Enhanced Mail (email encryption).

B. PPP: Point-to-Point Protocol (data link layer, not encryption).

C. IPSEC: VPN encryption protocol.

D. SET: Secure Electronic Transaction (used in payment systems, obsolete).

Guardster is an anonymizing proxy service that allows users to:

Mask their real IP address

Bypass content filters and access restricted websites

Maintain anonymity while browsing or engaging in online activities

It functions as a middleman between the user and target sites, hiding user identities.

Incorrect Options:

A. Baidu is a Chinese search engine.

C. WolframAlpha is a computational search engine.

D. Karma Decay is a reverse image search engine for Reddit.

Reference – CEH v13 Official Courseware:

Module 02: Footprinting and Reconnaissance

Section: “Anonymous Browsing Tools and Techniques”

Subsection: “Proxy and Anonymizing Services”

A vulnerability scan identifies known vulnerabilities by comparing system configurations and software versions against a database. It is mostly passive and does not confirm if vulnerabilities are exploitable.

Penetration testing, however, involves simulating real-world attacks. It attempts to actively exploit vulnerabilities, escalate privileges, and access sensitive data, offering a more realistic view of risk.

Reference – CEH v13 Official Study Guide:

Module 1: Introduction to Ethical Hacking

Quote:

“A penetration test goes beyond vulnerability identification by actively exploiting weaknesses to assess the actual risk and potential impact to the organization.”

Incorrect Options:

A. Scans do more than port scanning.

C. Penetration testing is often manual and detailed.

D. The difference is methodology, not just database size.

===========

Comprehensive and Detailed Explanation:

Host-based Intrusion Detection Systems (HIDS) run on individual hosts and monitor activities like file access, processes, and system logs. HIDS:

Detects attacks missed by NIDS (e.g., insider threats, encrypted traffic)

Monitors integrity of system files

Works in near real-time

Requires no additional network hardware

Can be implemented at low cost

From CEH v13 Courseware:

Module 13: IDS, Firewalls and Honeypots → Types of IDS (HIDS vs. NIDS)

ARIN (American Registry for Internet Numbers) is a Regional Internet Registry (RIR) that provides information about IP address allocations and autonomous systems in North America. It’s used for WHOIS lookups and footprinting in reconnaissance.

Comprehensive and Detailed Explanation From CEH v13 Guide:

Vulnerability identification is the step in the risk assessment process where security flaws or weaknesses are identified in existing systems, policies, or procedures.

CEH v13 Reference:

Module 5: Vulnerability Assessment – Risk Assessment Concepts

“Vulnerability identification is the process of discovering existing flaws and weaknesses in systems or processes that may be exploited.”

=============================================================

The longer an adversary has this level of access, the greater the impact. Defenders must detect this stage as quickly as possible and deploy tools which can enable them to gather forensic evidence. One example would come with network packet captures, for damage assessment. Only now, after progressing through the primary six phases, can intruders take actions to realize their original objectives. Typically, the target of knowledge exfiltration involves collecting, encrypting and extracting information from the victim(s) environment; violations of knowledge integrity or availability are potential objectives also . Alternatively, and most ordinarily , the intruder may only desire access to the initial victim box to be used as a hop point to compromise additional systems and move laterally inside the network. Once this stage is identified within an environment, the implementation of prepared reaction plans must be initiated. At a minimum, the plan should include a comprehensive communication plan, detailed evidence must be elevated to the very best ranking official or board , the deployment of end-point security tools to dam data loss and preparation for briefing a CIRT Team. Having these resources well established beforehand may be a “MUST” in today’s quickly evolving landscape of cybersecurity threats

Most likely have an issue with DNS.

DNS stands for “Domain Name System.” It’s a system that lets you connect to websites by matching human-readable domain names (like example.com) with the server's unique ID where a website is stored.

Think of the DNS system as the internet’s phonebook. It lists domain names with their corresponding identifiers called IP addresses, instead of listing people’s names with their phone numbers. When a user enters a domain name like wpbeginner.com on their device, it looks up the IP address and connects them to the physical location where that website is stored.

NOTE: Often DNS lookup information will be cached locally inside the querying computer or remotely in the DNS infrastructure. There are typically 8 steps in a DNS lookup. When DNS information is cached, steps are skipped from the DNS lookup process, making it quicker. The example below outlines all 8 steps when nothing is cached.

The 8 steps in a DNS lookup:

1. A user types ‘example.com’ into a web browser, and the query travels into the Internet and is received by a DNS recursive resolver;

2. The resolver then queries a DNS root nameserver;

3. The root server then responds to the resolver with the address of a Top-Level Domain (TLD) DNS server (such as .com or .net), which stores the information for its domains. When searching for example.com, our request is pointed toward the .com TLD;

4. The resolver then requests the .com TLD;

5. The TLD server then responds with the IP address of the domain’s nameserver, example.com;

6. Lastly, the recursive resolver sends a query to the domain’s nameserver;

7. The IP address for example.com is then returned to the resolver from the nameserver;

8. The DNS resolver then responds to the web browser with the IP address of the domain requested initially;

Once the 8 steps of the DNS lookup have returned the IP address for example.com, the browser can request the web page:

9. The browser makes an HTTP request to the IP address;

10. The server at that IP returns the webpage to be rendered in the browser.

NOTE 2: DNS primarily uses the User Datagram Protocol (UDP) on port number 53 to serve requests. And if this port is blocked, then a problem arises already in the first step. But the ninth step is performed without problems.

User-directed spidering is a technique that allows the hacker to manually browse the target website and use a proxy or spider tool to capture and analyze the traffic. This way, the hacker can discover hidden or dynamic content that standard web spiders may miss due to a specific file in the root directory, such as robots.txt, that instructs them not to crawl certain pages or directories. User-directed spidering can also help the hacker to bypass authentication or authorization mechanisms, as well as identify vulnerabilities or sensitive information in the target website. User-directed spidering can be performed with tools like Burp Suite and WebScarab, which are web application security testing tools that can intercept, modify, and replay HTTP requests and responses, as well as perform various attacks and scans on the target website.

The other options are not likely to achieve the same results as user-directed spidering. Using Photon to retrieve archived URLs of the target website from archive.org may provide some historical information about the website, but it may not reflect the current state or content of the website. Using the Netcraft tool to gather website information may provide some general information about the website, such as its IP address, domain name, server software, or hosting provider, but it may not reveal the specific files or web pages on the website. Examining HTML source code and cookies may provide some clues about the website’s structure, functionality, or user preferences, but it may not expose the hidden or dynamic content that user-directed spidering can discover. References:

User Directed Spidering with Burp

Web Spidering - What Are Web Crawlers & How to Control Them

Web Security: Recon

Mapping the Application for Penetrating Web Applications — 1

When a NULL scan is sent to a port on a UNIX-based system:

If the port is OPEN: The system does not respond at all.

If the port is CLOSED: The system responds with a RST packet.

This behavior is based on how the TCP stack processes unexpected packets.

From CEH v13 Courseware:

Module 3: Scanning Networks

Topic: Stealth Scanning Techniques → NULL Scan

CEH v13 Official Guide states:

“A NULL scan sends a TCP packet with no flags set. On systems following RFC 793 (like many Unix/Linux), open ports silently drop such packets (no response), while closed ports respond with a TCP RST.”

Incorrect Options:

A–E: Not standard responses for an open port in a NULL scan scenario.

Whitelist validation (also known as allowlist validation) is a robust defensive strategy where only pre-approved input formats are accepted. This includes:

Restricting input to specific data types (e.g., integer, string)

Limiting size, format, or allowed characters

Accepting only expected values (e.g., country codes, age ranges)

This practice is highly effective in mitigating SQL injection and other input-based attacks.

Incorrect Options:

A. Output encoding prevents XSS by encoding output but doesn't validate input.

B. Enforcing least privilege is an access control principle.

D. Blacklist validation is less secure and attempts to block known bad inputs, which may be bypassed.

Reference – CEH v13 Official Courseware:

Module 14: Hacking Web Applications

Section: “Input Validation and SQL Injection Mitigation”

Subsection: “Whitelist vs Blacklist Input Validation”

===========

In CEH v13 Module 14: Cryptography, key escrow is discussed as a recovery mechanism where a third party securely holds a cryptographic key for retrieval if it’s lost.

Key Escrow Characteristics:

Common in enterprise environments for systems like BitLocker.

Keys are automatically backed up to Active Directory (AD) for future retrieval.

Ensures that encrypted data is not permanently lost due to forgotten or deleted keys.

Option Clarification:

A. Key archival: Storing old keys for audit/record-keeping.

B. Key escrow: Correct – Third-party or central storage for recovery purposes.

C. Certificate rollover: Replacement of expiring certificates.

D. Key renewal: Generating a new key after expiration or compromise.

Passive OS fingerprinting involves observing traffic from a remote host and analyzing it to infer details about the operating system without actively sending packets or probes. This is useful in stealthy reconnaissance where avoiding detection is critical.

tcpdump is a packet analyzer that captures traffic in real time. By analyzing certain TCP/IP header fields such as TTL (Time-To-Live), window size, TCP options, and DF (Don't Fragment) flags, attackers can passively deduce the operating system of the target host.

CEH v13 Guide states:

“Passive fingerprinting tools like tcpdump and Wireshark allow the attacker to capture packets and analyze them for OS-specific traits, making it possible to identify the OS without sending packets to the target system.”

Reference – CEH v13 Study Guide:

Module 02: Footprinting and Reconnaissance, Section: “OS Fingerprinting Techniques”, Subsection: “Passive OS Fingerprinting”

Incorrect Options Explained:

A: nmap is primarily an active scanning tool (though it has limited passive capabilities).

C: tracert is used for tracing packet routes, not OS fingerprinting.

D: ping checks host availability and latency, not OS details.

‒‒‒‒‒‒‒‒‒‒‒‒‒‒‒

The official management decision given by a senior agency official to authorize operation of an information system and to explicitly accept the risk to agency operations (including mission, functions, image, or reputation), agency assets, or individuals, based on the implementation of an agreed-upon set of security controls.

formal declaration by a designated accrediting authority (DAA) or principal accrediting authority (PAA) that an information system is approved to operate at an acceptable level of risk, based on the implementation of an approved set of technical, managerial, and procedural safeguards. See authorization to operate (ATO). Rationale: The Risk Management Framework uses a new term to refer to this concept, and it is called authorization.

Identifies the information resources covered by an accreditation decision, as distinguished from separately accredited information resources that are interconnected or with which information is exchanged via messaging. Synonymous with Security Perimeter.

For the purposes of identifying the Protection Level for confidentiality of a system to be accredited, the system has a conceptual boundary that extends to all intended users of the system, both directly and indirectly connected, who receive output from the system. See authorization boundary. Rationale: The Risk Management Framework uses a new term to refer to the concept of accreditation, and it is called authorization. Extrapolating, the accreditation boundary would then be referred to as the authorization boundary.

In the context of security testing, test automation plays a critical role in improving the speed and consistency of testing activities. However, it cannot entirely replace manual testing because certain security vulnerabilities—especially logic flaws or issues with session management—often require human intuition and contextual understanding.

According to CEH v13 Official Courseware – Module 05 (Vulnerability Analysis), and confirmed in the CEH v13 Study Guide, automated testing is best suited for:

Repetitive benchmark tests

Regression testing

Scanning for known vulnerabilities

Ensuring consistency across environments

However, manual testing is still essential for:

Business logic testing

Security misconfiguration identification

Discovering zero-day flaws

DNS zone transfers occur when a secondary name server (slave) checks the Start of Authority (SOA) record from the primary server. The serial number in the SOA indicates the version of the zone file.

If:

Primary SOA serial > Secondary SOA serial

→ Zone transfer is initiated by the secondary server to update its data.

From CEH v13:

Module 3: DNS Enumeration

Topic: Zone Transfers and SOA Logic

CEH v13 Study Guide states:

“A secondary name server periodically queries the primary name server for changes. If the serial number in the SOA record is higher on the primary, it indicates a zone update, and a zone transfer is triggered.”

Incorrect Options:

B: Reversed condition

C/D: Restarting services doesn’t necessarily trigger a transfer

E: TTL expiration affects caching, not zone transfer logic

Comprehensive and Detailed Explanation:

Cryptographic hash functions provide:

Integrity: Any change in the input changes the output hash.

Collision Resistance: It is computationally infeasible to find two inputs that produce the same hash.

This ensures data is not altered during transmission.

From CEH v13 Courseware:

Module 10: Cryptography → Hashing Functions (e.g., SHA-256, MD5)

In a session donation attack, the attacker donates their own session ID to the target user. In this

attack, the attacker first obtains a valid session ID by logging into a service and later feeds the same session ID to the target user. This session ID links a target user to the attacker's account page without disclosing any information to the victim. When the target user clicks on the link and enters the details (username, password, payment details, etc.) in a form, the entered

details are linked to the attacker's account. To initiate this attack, the attacker can send their

session ID using techniques such as cross-site cooking, an MITM attack, and session fixation. A

session donation attack involves the following steps.

A stealth virus may be a sort of virus malware that contains sophisticated means of avoiding detection by antivirus software. After it manages to urge into the now-infected machine a stealth viruses hides itself by continually renaming and moving itself round the disc.

Like other viruses, a stealth virus can take hold of the many parts of one’s PC. When taking control of the PC and performing tasks, antivirus programs can detect it, but a stealth virus sees that coming and can rename then copy itself to a special drive or area on the disc, before the antivirus software. Once moved and renamed a stealth virus will usually replace the detected ‘infected’ file with a clean file that doesn’t trigger anti-virus detection. It’s a never-ending game of cat and mouse.

The intelligent architecture of this sort of virus about guarantees it’s impossible to completely rid oneself of it once infected. One would need to completely wipe the pc and rebuild it from scratch to completely eradicate the presence of a stealth virus. Using regularly-updated antivirus software can reduce risk, but, as we all know, antivirus software is additionally caught in an endless cycle of finding new threats and protecting against them.

https://www.techslang.com/definition/what-is-a-stealth-virus/

Comprehensive and Detailed Explanation From CEH v13 Guide:

R-U-Dead-Yet? (RUDY) is a DoS tool that targets web applications by sending slow HTTP POST requests with large Content-Length headers. This consumes server resources, leading to a denial of service.

CEH v13 Reference:

Module 9: Denial-of-Service – DoS Tools

“R-U-Dead-Yet? (RUDY) sends long-form POST requests to consume server-side sessions and exhaust resources without completing the transaction.”

The File Transfer Protocol (FTP) is a standard organization convention utilized for the exchange of PC records from a worker to a customer on a PC organization. FTP is based on a customer worker model engineering utilizing separate control and information associations between the customer and the server.[1] FTP clients may validate themselves with an unmistakable book sign-in convention, ordinarily as a username and secret key, however can interface namelessly if the worker is designed to permit it. For secure transmission that ensures the username and secret phrase, and scrambles the substance, FTP is frequently made sure about with SSL/TLS (FTPS) or supplanted with SSH File Transfer Protocol (SFTP).

The primary FTP customer applications were order line programs created prior to working frameworks had graphical UIs, are as yet dispatched with most Windows, Unix, and Linux working systems.[2][3] Many FTP customers and mechanization utilities have since been created for working areas, workers, cell phones, and equipment, and FTP has been fused into profitability applications, for example, HTML editors.

A SYN flood attack is a type of denial-of-service (DoS) attack that exploits the TCP handshake process by sending a large number of SYN requests to the target server, without completing the connection. This consumes the connection state tables on the server, preventing it from accepting new connections. The attacker has crafted an automated botnet to simultaneously send ‘s’ SYN packets per second to the server. The server can handle ‘f’ SYN packets per second without any performance issues. If ‘s’ exceeds ‘f’, the network infrastructure begins to show signs of overload. The system’s response time increases exponentially (24k), where ‘k’ represents each additional SYN packet above the ‘f’ limit.

Considering ‘s=500’ and different ‘f’ values, the scenario that is most likely to cause the server to experience overload and significantly increased response times is the one where ‘f=420’. This is because ‘s’ is greater than ‘f’ by 80 packets per second, which means the server cannot handle the incoming traffic and will eventually run out of resources. The response time shoots up (2480 = 281,474,976,710,656 times the normal response time), indicating a system overload.

The other scenarios are less likely or less severe than the one where ‘f=420’. Option A has ‘f=510’, which is greater than ‘s’, so the system stays stable and the response time remains unaffected. Option B has ‘f=495’, which is less than ‘s’ by 5 packets per second, so the response time drastically rises (245 = 32 times the normal response time), indicating a probable system overload, but not as extreme as option D. Option C has ‘f=505’, which is less than ‘s’ by 5 packets per second, so the response time increases but not as drastically (245 = 32 times the normal response time), and the system might still function, albeit slowly. References:

SYN flood DDoS attack | Cloudflare

SYN flood - Wikipedia

What Is a SYN Flood Attack? | F5

What is a SYN flood attack and how to prevent it? | NETSCOUT

The Blackjacking attack involves leveraging a compromised BlackBerry device and its connection through the BlackBerry Enterprise Server (BES) to tunnel back into the internal corporate network, bypassing perimeter firewalls. The tool used in this method is BBProxy.

BBProxy is installed on the BlackBerry device and establishes a covert tunnel via BES, allowing attackers to pivot into the internal LAN from outside the perimeter.

Reference – CEH v13 Official Study Guide:

Module 17: Hacking Mobile Platforms

Quote:

“Blackjacking is a technique in which attackers use BBProxy to exploit a trusted path from a BlackBerry device to the corporate LAN through BES.”

Incorrect Options Explained:

A. Paros Proxy is a web proxy used for intercepting HTTP/S traffic.

C. Blooover is used for Bluetooth security auditing.

D. BBCrack is used for password recovery on BlackBerry devices, not for tunneling.

===========

In CEH v13 Module 05: System Hacking, once an attacker gains access to hashed passwords, cracking tools are employed to reverse or brute-force them.

Tool Breakdown:

John the Ripper: A powerful password cracking tool that supports many hash formats.

Hashcat: GPU-based, extremely fast password hash cracking tool.

THC-Hydra: Used for online attacks (e.g., SSH, FTP brute force).

Netcat: Not a password cracking tool — it’s a network utility used for:

Remote shell connections

Banner grabbing

File transfers

Port scanning

Therefore:

C. Netcat is the correct answer — it is not used for password cracking.

The host-based vulnerability assessment (VA) resolution arose from the auditors’ got to periodically review systems. Arising before the net becoming common, these tools typically take an “administrator’s eye” read of the setting by evaluating all of the knowledge that an administrator has at his or her disposal.

Uses

Host VA tools verify system configuration, user directories, file systems, registry settings, and all forms of other info on a number to gain information about it. Then, it evaluates the chance of compromise. it should also live compliance to a predefined company policy so as to satisfy an annual audit. With administrator access, the scans area unit less possible to disrupt traditional operations since the computer code has the access it has to see into the complete configuration of the system.

What it Measures Host

VA tools will examine the native configuration tables and registries to spot not solely apparent vulnerabilities, however additionally “dormant” vulnerabilities – those weak or misconfigured systems and settings which will be exploited when an initial entry into the setting. Host VA solutions will assess the safety settings of a user account table; the access management lists related to sensitive files or data; and specific levels of trust applied to other systems. The host VA resolution will a lot of accurately verify the extent of the danger by determinant however way any specific exploit could also be ready to get.

Types of Vulnerability Assessment Host-based assessments are a type of security check that involve conducting a configuration-level check to identify system configurations, user directories, file systems, registry settings, and other parameters to evaluate the possibility of compromise. 
Host-based scanners assess systems to identify vulnerabilities such as native configuration tables, incorrect registry or file permissions, and software configuration errors. (P.528/512)

Burp Suite is a comprehensive web vulnerability scanner and testing suite widely used in penetration testing and ethical hacking.

Key features include:

Intercepting proxy: Allows inspection and modification of traffic between the browser and target server.

Session hijacking/testing tools

Intruder and Repeater modules for customized payload injection

Sequencer module for testing session token randomness

Extensibility through plugins and custom scripts

Incorrect Options:

A. Nmap is a network scanning tool, not used for intercepting web traffic.

C. CxSAST (Checkmarx) is a static application security testing (SAST) tool.

D. Wireshark is a packet analyzer but does not include intercepting proxy features or token testing.

Reference – CEH v13 Official Courseware:

Module 14: Hacking Web Applications

Section: “Burp Suite as a Web Vulnerability Testing Tool”

CEH iLab: Using Burp Suite for Web App Testing

===========

In CEH v13 Module 12: Hacking Web Applications, Burp Suite is introduced as a powerful proxy-based tool used for intercepting, modifying, and analyzing HTTP/S traffic between a client and a web application.

Key Features of Burp Suite:

Captures all HTTP requests and responses.

Allows for manual testing of input parameters, headers, and cookies.

Includes tools such as Intruder, Repeater, Scanner, and Decoder.

Helps detect vulnerabilities such as XSS, SQLi, CSRF, and insecure session handling.

Option Review:

A. Maskgen: Used for generating masks, not a web proxy.

B. Dimitry: A footprinting tool, not used for request/response testing.

C. Burpsuite: Correct. Designed for web application vulnerability analysis.

D. Proxychains: Used to chain proxies for anonymity, not for HTTP traffic analysis.

PGP (Pretty Good Privacy), SSL (Secure Sockets Layer), and IKE (Internet Key Exchange) use Public Key Cryptography for secure communication. They utilize:

Public and private key pairs

Asymmetric encryption for key exchange

Symmetric encryption for data confidentiality (after key exchange)

These protocols ensure secure data transfer over insecure networks.

Reference – CEH v13 Official Study Guide:

Module 20: Cryptography

Quote:

“Public key cryptography uses asymmetric key pairs for encryption and authentication. Protocols like PGP, SSL/TLS, and IKE rely on this to exchange keys and establish trust.”

Incorrect Options:

A & D. Digest/hash algorithms (e.g., MD5, SHA) ensure integrity, not encryption

B. Secret key refers to symmetric encryption, which is used after the public key exchange, not as the basis for these protocols

An iPhone client’s most noticeably terrible bad dream is to have somebody oversee his/her gadget, including the capacity to record and control all action without waiting be in a similar room. In this blog entry, we present another weakness called “Trustjacking”, which permits an aggressor to do precisely that.

This weakness misuses an iOS highlight called iTunes Wi-Fi sync, which permits a client to deal with their iOS gadget without genuinely interfacing it to their PC. A solitary tap by the iOS gadget proprietor when the two are associated with a similar organization permits an assailant to oversee the gadget. Furthermore, we will stroll through past related weaknesses and show the progressions that iPhone has made to alleviate them, and why these are adequately not to forestall comparative assaults.

After interfacing an iOS gadget to another PC, the clients are being found out if they trust the associated PC or not. Deciding to believe the PC permits it to speak with the iOS gadget by means of the standard iTunes APIs.

This permits the PC to get to the photographs on the gadget, perform reinforcement, introduce applications and considerably more, without requiring another affirmation from the client and with no recognizable sign. Besides, this permits enacting the “iTunes Wi-Fi sync” highlight, which makes it conceivable to proceed with this sort of correspondence with the gadget even after it has been detached from the PC, as long as the PC and the iOS gadget are associated with a similar organization. It is intriguing to take note of that empowering “iTunes Wi-Fi sync” doesn’t need the casualty’s endorsement and can be directed simply from the PC side.

Getting a live stream of the gadget’s screen should be possible effectively by consistently requesting screen captures and showing or recording them distantly.

It is imperative to take note of that other than the underlying single purpose of disappointment, approving the vindictive PC, there is no other component that forestalls this proceeded with access. Likewise, there isn’t anything that informs the clients that by approving the PC they permit admittance to their gadget even in the wake of detaching the USB link.

Agent-based scanners reside on a single machine but can scan several machines on the same network.

Network-based scanner

A network-based vulnerability scanner, in simplistic terms, is the process of identifying loopholes on a computer’s network or IT assets, which hackers and threat actors can exploit. By implementing this process, one can successfully identify their organization’s current risk(s). This is not where the buck stops; one can also verify the effectiveness of your system's security measures while improving internal and external defenses. Through this review, an organization is well equipped to take an extensive inventory of all systems, including operating systems, installed software, security patches, hardware, firewalls, anti-virus software, and much more.

Agent-based scanner

Agent-based scanners make use of software scanners on each and every device; the results of the scans are reported back to the central server. Such scanners are well equipped to find and report out on a range of vulnerabilities.

NOTE: This option is not suitable for us, since for it to work, you need to install a special agent on each computer before you start collecting data from them.

In CEH v13 Module 02: Footprinting and Reconnaissance, Dark Web Footprinting is discussed as an advanced form of reconnaissance where attackers access hidden services and data using anonymity networks such as Tor (The Onion Router), I2P, or Freenet. These networks enable access to the deep web and dark web, where unindexed, and often illicit, content resides.

Key points relevant to this scenario:

The attacker encrypted browsing traffic and navigated anonymously, which strongly implies the use of tools like Tor or VPNs to mask identity.

The attacker used specialized tools/search engines like:

Torch

Ahmia

DarkSearch

Candle

The goal was to find sensitive or hidden information in government or federal systems — a common dark web footprinting objective.

The final step involved an attack that left no trace, which aligns with using the dark web for anonymity and obfuscation.

Option Analysis:

A. Dark web footprinting

Correct. This matches the behavior described: encrypted, anonymous access to sensitive information through dark web tools.

B. VoIP footprinting ❌

Incorrect. VoIP footprinting relates to identifying vulnerabilities or metadata in Voice over IP systems, not anonymous browsing or dark web activities.

C. VPN footprinting ❌

Incorrect. While VPNs may be used as part of anonymity, VPN footprinting refers to identifying systems using VPNs — not the act of gathering data anonymously.

D. Website footprinting ❌

Incorrect. Website footprinting involves gathering information from public-facing websites, like WHOIS data, robots.txt, and HTML metadata — not hidden dark web content.

Reference from CEH v13 Study Guide and Courseware:

Module 02 – Footprinting and Reconnaissance, Section: Footprinting through Dark Web and Deep Web

CEH v13 iLabs: Using Tor and Dark Web Search Engines for Reconnaissance

CEH Engage – Phase 1 (Reconnaissance): Dark Web Intelligence Gathering

Non-repudiation is the assurance that someone cannot deny the validity of something. Non-repudiation is a legal concept that is widely used in information security and refers to a service, which provides proof of the origin of data and the integrity of the data. In other words, non-repudiation makes it very difficult to successfully deny who/where a message came from as well as the authenticity and integrity of that message.

Regional Internet Registries (RIRs):

ARIN (American Registry for Internet Numbers)

AFRINIC (African Network Information Center)

APNIC (Asia Pacific Network Information Center)

RIPE (Réseaux IP Européens Network Coordination Centre)

LACNIC (Latin American and Caribbean Network Information Center)

Web Server Attacks - DNS Server Hijacking Attacker compromises the DNS server and changes the DNS settings so that all the requests coming towards the target web server are redirected to his/her own malicious server. (P.1623/1607)

«Many IDS reassemble communication streams; hence, if a packet is not received within a reasonable period, many IDS stop reassembling and handling that stream. If the application under attack keeps a session active for a longer time than that spent by the IDS on reassembling it, the IDS will stop. As a result, any session after the IDS stops reassembling the sessions will be susceptible to malicious data theft by attackers. The IDS will not log any attack attempt after a successful splicing attack. Attackers can use tools such as Nessus for session splicing attacks.»

Did you know that the EC-Council exam shows how well you know their official book? So, there is no "Whisker" in it. In the chapter "Evading IDS" -> "Session Splicing", the recommended tool for performing a session-splicing attack is Nessus. Where Wisker came from is not entirely clear, but I will assume the author of the question found it while copying Wikipedia.

https://en.wikipedia.org/wiki/Intrusion_detection_system_evasion_techniques

One basic technique is to split the attack payload into multiple small packets so that the IDS must reassemble the packet stream to detect the attack. A simple way of splitting packets is by fragmenting them, but an adversary can also simply craft packets with small payloads. The 'whisker' evasion tool calls crafting packets with small payloads 'session splicing'.

By itself, small packets will not evade any IDS that reassembles packet streams. However, small packets can be further modified in order to complicate reassembly and detection. One evasion technique is to pause between sending parts of the attack, hoping that the IDS will time out before the target computer does. A second evasion technique is to send the packets out of order, confusing simple packet re-assemblers but not the target computer.

NOTE: Yes, I found scraps of information about the tool that existed in 2012, but I can not give you unverified information. According to the official tutorials, the correct answer is Nessus, but if you know anything about Wisker, please write in the QA section. Maybe this question will be updated soon, but I'm not sure about that.

Comprehensive and Detailed Explanation:

The OpenSSL command-line utility s_client is used to test SSL/TLS connections.

Correct syntax:

openssl s_client -connect www.website.com:443

This command will initiate a TLS connection to port 443 on the given domain and allow you to inspect certificates, cipher suites, and server responses.

From CEH v13 Courseware:

Module 12: Cryptography → SSL/TLS Testing Tools

If SNMP access is restricted to specific IP addresses (e.g., 192.168.1.0/24), you can bypass access controls by:

Spoofing the source IP to fall within that allowed range.

Using a SNMP set request to instruct the device (e.g., to copy its configuration to a TFTP server).

This is a classic SNMP spoofing attack.

From CEH v13 Courseware:

Module 4: Enumeration → SNMP Enumeration Attacks

A digital certificate, issued by a trusted Certificate Authority (CA), binds a public key to the identity of an entity (e.g., user, organization). This provides a means to validate ownership of the public key.

CEH v13 Reference:

Module 17: Cryptography

"A digital certificate ensures the authenticity of the public key through a trusted third party known as a Certificate Authority."

━━━━━━━━━━━━━━━━━━━━━━

https://www.cisco.com/c/en/us/support/docs/ip/access-lists/26448-ACLsamples.html

Since the first line prohibits any TCP traffic (access-list 102 deny tcp any any), the lines below will simply be ignored by the router. Below you will find the example from CISCO documentation.

This figure shows that FTP (TCP, port 21) and FTP data (port 20) traffic sourced from NetB destined to NetA is denied, while all other IP traffic is permitted.

FTP uses port 21 and port 20. TCP traffic destined to port 21 and port 20 is denied and everything else is explicitly permitted.

access-list 102 deny tcp any any eq ftp

access-list 102 deny tcp any any eq ftp-data

access-list 102 permit ip any any

https://linuxsecurityblog.com/2018/12/23/create-a-backdoor-with-cryptcat/

Cryptcat enables us to communicate between two systems and encrypts the communication between them with twofish, one of many excellent encryption algorithms from Bruce Schneier et al. Twofish’s encryption is on par with AES encryption, making it nearly bulletproof. In this way, the IDS can’t detect the malicious behavior taking place even when its traveling across normal HTTP ports like 80 and 443.

Many network and system administrators don't pay enough attention to system clock accuracy and time synchronization. Computer clocks can run faster or slower over time, batteries and power sources die, or daylight-saving time changes are forgotten. Sure, there are many more pressing security issues to deal with, but not ensuring that the time on network devices is synchronized can cause problems. And these problems often only come to light after a security incident.

If you suspect a hacker is accessing your network, for example, you will want to analyze your log files to look for any suspicious activity. If your network's security devices do not have synchronized times, the timestamps' inaccuracy makes it impossible to correlate log files from different sources. Not only will you have difficulty in tracking events, but you will also find it difficult to use such evidence in court; you won't be able to illustrate a smooth progression of events as they occurred throughout your network.

In CEH v13 Module 06: Malware Threats, the Cyber Kill Chain is broken down into its seven stages:

Reconnaissance

Weaponization

Delivery

Exploitation

Installation

Command & Control

Actions on Objectives

Step 3 – Delivery:

Refers to the transmission of the malicious payload to the victim.

Can occur through email, web downloads, USB drives, etc.

Correct Example:

A. “An intruder sends a malicious attachment via email to a target” — This is delivery.

Other Options:

B. Weaponization

C. Exploitation

D. Installation

Symmetric encryption is a method of encrypting and decrypting data using the same secret key. Symmetric encryption is fast and efficient, but it requires a secure way of managing and distributing the keys to the users who need them. If the keys are compromised, the data is no longer secure.

One of the strategies to securely manage and distribute symmetric keys is to use HTTPS protocol for secure key transfer. HTTPS is a protocol that uses SSL/TLS to encrypt the communication between a client and a server over the Internet. HTTPS can protect the symmetric keys from being intercepted or modified by an attacker during the key transfer process. HTTPS can also authenticate the server and the client using certificates, ensuring that the keys are sent to and received by the intended parties.

To use HTTPS protocol for secure key transfer, the development team needs to implement the following steps1:

Generate a symmetric key for each user who wants to store their files on the cloud storage platform. The symmetric key will be used to encrypt and decrypt the user’s files.

Generate a certificate for the cloud storage server. The certificate will contain the server’s public key and other information, such as the server’s domain name, the issuer, and the validity period. The certificate will be signed by a trusted certificate authority (CA), which is a third-party entity that verifies the identity and legitimacy of the server.

Install the certificate on the cloud storage server and configure the server to use HTTPS protocol for communication.

When a user wants to upload or download their files, the user’s client (such as a web browser or an app) will initiate a HTTPS connection with the cloud storage server. The client will verify the server’s certificate and establish a secure session with the server using SSL/TLS. The client and the server will negotiate a session key, which is a temporary symmetric key that will be used to encrypt the data exchanged during the session.

The cloud storage server will send the user’s symmetric key to the user’s client, encrypted with the session key. The user’s client will decrypt the symmetric key with the session key and use it to encrypt or decrypt the user’s files.

The user’s client will store the symmetric key securely on the user’s device, such as in a password-protected file or a hardware token. The user’s client will also delete the session key after the session is over.

Using HTTPS protocol for secure key transfer can ensure that the symmetric keys are protected from eavesdropping, tampering, or spoofing attacks. However, this strategy also has some challenges and limitations, such as:

The development team needs to obtain and maintain valid certificates for the cloud storage server from a trusted CA, which might incur costs and administrative overhead.

The users need to trust the CA that issued the certificates for the cloud storage server and verify the certificates before accepting them.

The users need to protect their symmetric keys from being lost, stolen, or corrupted on their devices. The development team needs to provide a mechanism for key backup, recovery, or revocation in case of such events.

The users need to update their symmetric keys periodically to prevent key exhaustion or reuse attacks. The development team needs to provide a mechanism for key rotation or renewal in a secure and efficient manner.

A mirror site may be a website or set of files on a computer server that has been copied to a different computer server in order that the location or files are available from quite one place. A mirror site has its own URL, but is otherwise just like the principal site. Load-balancing devices allow high-volume sites to scale easily, dividing the work between multiple mirror sites.

A mirror site is typically updated frequently to make sure it reflects the contents of the first site. In some cases, the first site may arrange for a mirror site at a bigger location with a better speed connection and, perhaps, a better proximity to an outsized audience.

If the first site generates an excessive amount of traffic, a mirror site can ensure better availability of the web site or files. For websites that provide copies or updates of widely used software, a mirror site allows the location to handle larger demands and enables the downloaded files to arrive more quickly. Microsoft, Sun Microsystems and other companies have mirror sites from which their browser software are often downloaded.

Mirror sites are wont to make site access faster when the first site could also be geographically distant from those accessing it. A mirrored web server is usually located on a special continent from the principal site, allowing users on the brink of the mirror site to urge faster and more reliable access.

Mirroring an internet site also can be done to make sure that information are often made available to places where access could also be unreliable or censored. In 2013, when Chinese authorities blocked access to foreign media outlets just like the Wall Street Journal and Reuters, site mirroring was wont to restore access and circumvent government censorship.

Out-of-band SQL injection occurs when an attacker is unable to use an equivalent channel to launch the attack and gather results. … Out-of-band SQLi techniques would believe the database server’s ability to form DNS or HTTP requests to deliver data to an attacker. Out-of-band SQL injection is not very common, mostly because it depends on features being enabled on the database server being used by the web application. Out-of-band SQL injection occurs when an attacker is unable to use the same channel to launch the attack and gather results.

Out-of-band techniques, offer an attacker an alternative to inferential time-based techniques, especially if the server responses are not very stable (making an inferential time-based attack unreliable).

Out-of-band SQLi techniques would rely on the database server’s ability to make DNS or HTTP requests to deliver data to an attacker. Such is the case with Microsoft SQL Server’s xp_dirtree command, which can be used to make DNS requests to a server an attacker controls; as well as Oracle Database’s UTL_HTTP package, which can be used to send HTTP requests from SQL and PL/SQL to a server an attacker controls.

Comprehensive and Detailed Explanation:

The correct file name is /var/log/auth.log (not auth.fesg). “auth.fesg” is a typo or does not exist by default in Linux systems.

Linux login records include:

/var/log/auth.log – authentication logs

/var/log/wtmp – records login sessions

/var/log/btmp – records failed logins

/var/log/user.log – logs user-level messages (optional)

Therefore, B is not a valid log file.

From CEH v13 Courseware:

Module 6: System Hacking → Covering Tracks in Linux

The Sarbanes-Oxley Act of 2002 could be a law the U.S. Congress passed on July thirty of that year to assist defend investors from fallacious money coverage by companies.Also called the SOX Act of 2002 and also the company Responsibility Act of 2002, it mandated strict reforms to existing securities rules and obligatory powerful new penalties on law breakers.

The Sarbanes-Oxley law Act of 2002 came in response to money scandals within the early 2000s involving in public listed corporations like Enron Corporation, Tyco International plc, and WorldCom. The high-profile frauds cask capitalist confidence within the trustiness of company money statements Associate in Nursingd light-emitting diode several to demand an overhaul of decades-old restrictive standards.

In CEH v13 Module 14: Cryptography, Serpent is detailed as one of the finalists in the Advanced Encryption Standard (AES) competition, known for its strong security characteristics.

Key Features of Serpent:

128-bit block size, and key sizes of 128, 192, or 256 bits.

Uses 32 rounds of substitution and permutation.

Operates on four 32-bit words per block.

Employs 8 different S-boxes, each with a 4-bit input and 4-bit output.

Designed to provide high security and resistance against differential cryptanalysis.

Option Clarification:

A. TEA: Uses a Feistel structure with simple operations, but not 32 rounds with S-boxes.

B. CAST-128: Has 64-bit block size and fewer rounds.

C. RC5: Variable block and key sizes but doesn’t use 32 rounds with fixed S-box design.

D. Serpent: Matches all given features.

Kernel-mode rootkits run with the best operating system privileges (Ring 0) by adding code or replacement parts of the core operating system, as well as each the kernel and associated device drivers. Most operative systems support kernel-mode device drivers, that execute with a similar privileges because the software itself. As such, several kernel-mode rootkits square measure developed as device drivers or loadable modules, like loadable kernel modules in Linux or device drivers in Microsoft Windows. This category of rootkit has unrestricted security access, however is tougher to jot down. The quality makes bugs common, and any bugs in code operative at the kernel level could seriously impact system stability, resulting in discovery of the rootkit. one amongst the primary wide familiar kernel rootkits was developed for Windows NT four.0 and discharged in Phrack magazine in 1999 by Greg Hoglund. Kernel rootkits is particularly tough to observe and take away as a result of they operate at a similar security level because the software itself, and square measure therefore able to intercept or subvert the foremost sure software operations. Any package, like antivirus package, running on the compromised system is equally vulnerable. during this scenario, no a part of the system is sure.

https://nmap.org/book/man-output.html

-oX - Requests that XML output be directed to the given filename.

https://en.wikipedia.org/wiki/Presentation_layer

In the seven-layer OSI model of computer networking, the presentation layer is layer 6 and serves as the data translator for the network. It is sometimes called the syntax layer. The presentation layer is responsible for the formatting and delivery of information to the application layer for further processing or display.

Encryption is typically done at this level too, although it can be done on the application, session, transport, or network layers, each having its own advantages and disadvantages. Decryption is also handled at the presentation layer. For example, when logging on to bank account sites the presentation layer will decrypt the data as it is received.

In an inference-based assessment, scanning starts by building an inventory of the protocols found on the machine. After finding a protocol, the scanning process starts to detect which ports are attached to services, such as an email server, web server, or database server. After finding services, it selects vulnerabilities on each machine and starts to execute only those relevant tests.

Firewalking is a technique used to determine what layer 4 protocols a firewall will allow by sending crafted packets with TTL values that expire at the firewall and analyzing ICMP Time Exceeded responses. This helps in determining what ports and services are allowed through a firewall.

???? Reference – CEH v13 Study Guide, Module 11: Evading IDS, Firewalls, and Honeypots

“Firewalking is a technique used to gather information about firewalls and their rule sets by sending packets with TTL values that expire at the firewall.”

❌ Incorrect options:

A. Session hijacking refers to taking over an active session.

C. MITM attacks involve intercepting communications between two parties.

D. Network sniffing involves capturing packets, not probing firewall rules.

Comprehensive and Detailed Explanation:

A rubber-hose attack refers to extracting cryptographic secrets by means of physical coercion, threats, or torture, rather than technical attacks on the algorithm or implementation.

From CEH v13 Official Study Guide:

Module 10: Cryptography → Types of Attacks

“A rubber-hose attack bypasses technical security by attacking the human element.”

Footprinting is the first phase of ethical hacking and information gathering. It involves collecting as much information as possible about a target system or organization from public sources (such as websites, social media, WHOIS databases, job postings, etc.) before launching an attack or vulnerability scan.

???? Reference – CEH v13 Official Study Guide, Module 1: Introduction to Ethical Hacking

“Footprinting is the process of gathering information about a target system to find ways to intrude into the system.”

❌ Incorrect options:

A. Scanning is the next phase, involving probing the network.

C. Enumeration extracts detailed information from services like SNMP, NetBIOS, etc.

D. System Hacking is the actual exploitation phase.

Implementing regular firmware updates for all IoT devices is the primary recommendation to prevent DDoS attacks on the smart city project. Firmware updates can fix security vulnerabilities, patch bugs, and improve performance of the IoT devices, making them less susceptible to malware infections and botnet recruitment12. Firmware updates can also enable new security features, such as encryption, authentication, and firewall, that can protect the IoT devices from unauthorized access and data theft3. Firmware updates should be done automatically or remotely, without requiring user intervention, to ensure timely and consistent security across the IoT network4.

The other options are not as effective or feasible as firmware updates for the following reasons:

B. Deploying network intrusion detection systems (IDS) across the IoT network can help detect and alert DDoS attacks, but not prevent them. IDS can monitor network traffic and identify malicious patterns, such as high volume, spoofed IP addresses, or unusual protocols, that indicate a DDoS attack5. However, IDS cannot block or mitigate the attack, and may even be overwhelmed by the flood of traffic, resulting in false positives or missed alerts. Moreover, deploying IDS across a vast network of IoT devices can be costly, complex, and resource-intensive, as it requires dedicated hardware, software, and personnel.

C. Establishing strong, unique passwords for each IoT device can prevent unauthorized access and brute-force attacks, but not DDoS attacks. Passwords can protect the IoT devices from being compromised by hackers who try to guess or crack the default or weak credentials. However, passwords cannot prevent DDoS attacks that exploit known or unknown vulnerabilities in the IoT devices, such as buffer overflows, command injections, or protocol flaws. Moreover, establishing and managing strong, unique passwords for each IoT device can be challenging and impractical, as it requires user awareness, memory, and effort.

D. Implementing IP address whitelisting for all IoT devices can restrict network access and communication to trusted sources, but not DDoS attacks. IP address whitelisting can filter out unwanted or malicious traffic by allowing only the predefined IP addresses to connect to the IoT devices. However, IP address whitelisting cannot prevent DDoS attacks that use spoofed or legitimate IP addresses, such as reflection or amplification attacks, that bypass the whitelisting rules. Moreover, implementing IP address whitelisting for all IoT devices can be difficult and risky, as it requires constant updating, testing, and monitoring of the whitelist, and may block legitimate or emergency traffic by mistake.

https://en.wikipedia.org/wiki/Salt_(cryptography)

A salt is random data that is used as an additional input to a one-way function that hashes data, a password, or passphrase. Salts are used to safeguard passwords in storage. Historically a password was stored in plaintext on a system, but over time additional safeguards were developed to protect a user's password against being read from the system. A salt is one of those methods.

A new salt is randomly generated for each password. In a typical setting, the salt and the password (or its version after key stretching) are concatenated and processed with a cryptographic hash function, and the output hash value (but not the original password) is stored with the salt in a database. Hashing allows for later authentication without keeping and therefore risking exposure of the plaintext password in the event that the authentication data store is compromised.

Salts defend against a pre-computed hash attack, e.g. rainbow tables. Since salts do not have to be memorized by humans they can make the size of the hash table required for a successful attack prohibitively large without placing a burden on the users. Since salts are different in each case, they also protect commonly used passwords, or those users who use the same password on several sites, by making all salted hash instances for the same password different from each other.

https://en.wikipedia.org/wiki/IPsec

Internet Protocol Security (IPsec) is a secure network protocol suite that authenticates and encrypts the packets of data to provide secure encrypted communication between two computers over an Internet Protocol network. It is used in virtual private networks (VPNs).

IPsec includes protocols for establishing mutual authentication between agents at the beginning of a session and negotiation of cryptographic keys to use during the session. IPsec can protect data flows between a pair of hosts (host-to-host), between a pair of security gateways (network-to-network), or between a security gateway and a host (network-to-host). IPsec uses cryptographic security services to protect communications over Internet Protocol (IP) networks. It supports network-level peer authentication, data-origin authentication, data integrity, data confidentiality (encryption), and replay protection.

The initial IPv4 suite was developed with few security provisions. As a part of the IPv4 enhancement, IPsec is a layer 3 OSI model or internet layer end-to-end security scheme. In contrast, while some other Internet security systems in widespread use operate above layer 3, such as Transport Layer Security (TLS) that operates at the Transport Layer and Secure Shell (SSH) that operates at the Application layer, IPsec can automatically secure applications at the IP layer.

Agent Smith Attack

Agent Smith attacks are carried out by luring victims into downloading and installing malicious

apps designed and published by attackers in the form of games, photo editors, or other

attractive tools from third-party app stores such as 9Apps. Once the user has installed the app,

the core malicious code inside the application infects or replaces the legitimate apps in the

victim's mobile device C&C commands. The deceptive application replaces legitimate apps such

as WhatsApp, SHAREit, and MX Player with similar infected versions. The application sometimes

also appears to be an authentic Google product such as Google Updater or Themes. The

attacker then produces a massive volume of irrelevant and fraudulent advertisements on the

victim's device through the infected app for financial gain. Attackers exploit these apps to steal

critical information such as personal information, credentials, and bank details, from the

victim's mobile device through C&C commands.

Replay Attack could be a variety of security attack to the info sent over a network.

In this attack, the hacker or a person with unauthorized access, captures the traffic and sends communication to its original destination, acting because the original sender. The receiver feels that it’s Associate in Nursing genuine message however it’s really the message sent by the aggressor. the most feature of the Replay Attack is that the consumer would receive the message double, thence the name, Replay Attack.

Prevention from Replay Attack :

1. Timestamp technique –

Prevention from such attackers is feasible, if timestamp is employed at the side of the info. Supposedly, the timestamp on an information is over a precise limit, it may be discarded, and sender may be asked to send the info once more.

2. Session key technique –

Another way of hindrance, is by victimisation session key. This key may be used one time (by sender and receiver) per dealing, and can’t be reused.

Comprehensive and Detailed Explanation:

Script Kiddies are individuals with minimal technical skills who use existing tools or scripts developed by others to perform attacks. They generally do not understand the underlying mechanisms and rely on publicly available hacking tools.

From CEH v13 Official Study Guide:

Module 1: Introduction to Ethical Hacking → Hacker Types

“Script kiddies are unskilled attackers who use tools created by others.”

DNS uses Ports 53 which is almost always open on systems, firewalls, and clients to transmit DNS queries. instead of the more familiar Transmission Control Protocol (TCP) these queries use User Datagram Protocol (UDP) due to its low-latency, bandwidth and resource usage compared TCP-equivalent queries. UDP has no error or flow-control capabilities, nor does it have any integrity checking to make sure the info arrived intact.

How is internet use (browsing, apps, chat etc) so reliable then? If the UDP DNS query fails (it’s a best-effort protocol after all) within the first instance, most systems will retry variety of times and only after multiple failures, potentially switch to TCP before trying again; TCP is additionally used if the DNS query exceeds the restrictions of the UDP datagram size – typically 512 bytes for DNS but can depend upon system settings.

Figure 1 below illustrates the essential process of how DNS operates: the client sends a question string (for example, mail.google[.]com during this case) with a particular type – typically A for a number address. I’ve skipped the part whereby intermediate DNS systems may need to establish where ‘.com’ exists, before checking out where ‘google[.]com’ are often found, and so on.

Many worms and scanners are created to seek out and exploit systems running telnet. Given these facts, it’s really no surprise that telnet is usually seen on the highest Ten Target Ports list. Several of the vulnerabilities of telnet are fixed. They require only an upgrade to the foremost current version of the telnet Daemon or OS upgrade. As is usually the case, this upgrade has not been performed on variety of devices. this might flow from to the very fact that a lot of systems administrators and users don’t fully understand the risks involved using telnet. Unfortunately, the sole solution for a few of telnets vulnerabilities is to completely discontinue its use. the well-liked method of mitigating all of telnets vulnerabilities is replacing it with alternate protocols like ssh. Ssh is capable of providing many of an equivalent functions as telnet and a number of other additional services typical handled by other protocols like FTP and Xwindows. Ssh does still have several drawbacks to beat before it can completely replace telnet. it’s typically only supported on newer equipment. It requires processor and memory resources to perform the info encryption and decryption. It also requires greater bandwidth than telnet thanks to the encryption of the info . This paper was written to assist clarify how dangerous the utilization of telnet are often and to supply solutions to alleviate the main known threats so as to enhance the general security of the web

Once a reputation is resolved to an IP caching also helps: the resolved name-to-IP is usually cached on the local system (and possibly on intermediate DNS servers) for a period of your time . Subsequent queries for an equivalent name from an equivalent client then don’t leave the local system until said cache expires. Of course, once the IP address of the remote service is understood , applications can use that information to enable other TCP-based protocols, like HTTP, to try to to their actual work, for instance ensuring internet cat GIFs are often reliably shared together with your colleagues.

So, beat all, a couple of dozen extra UDP DNS queries from an organization’s network would be fairly inconspicuous and will leave a malicious payload to beacon bent an adversary; commands could even be received to the requesting application for processing with little difficulty.

Comprehensive and Detailed Explanation:

LDAP (Lightweight Directory Access Protocol) uses:

TCP/UDP port 389 for standard LDAP communication.

TCP/UDP port 636 for secure LDAP over SSL (LDAPS).

From CEH v13 Courseware:

Module 3: Scanning Networks → Common Ports and Protocols

Incorrect Options:

A: Port 110 = POP3

C: Port 464 = Kerberos change/set password

D: Port 445 = SMB over TCP/IP (used for file sharing)

A Protocol Analyzer is the correct tool used to examine the contents of packet data (often stored in .pcap files) to determine if a particular sequence of traffic is suspicious, malformed, or part of a known exploit.

In CEH v13:

Module 3: Scanning Networks

Module 4: Enumeration

Module 5: Vulnerability Analysis

Related Lab: Packet Analysis using Wireshark

The CEH v13 Study Guide states:

“A protocol analyzer (e.g., Wireshark) captures and decodes packets to display their contents and help analysts understand communication flows and anomalies. It is used to manually inspect packet contents and behavior, which helps distinguish legitimate traffic from attacks.”

PCAP (Packet Capture) files are typically analyzed using tools like Wireshark. These tools decode protocol layers and show payloads, making it easier for analysts to identify if IDS alerts were accurate or false positives.

Incorrect Options:

B. Network sniffer: General term; protocol analyzer is the specific functional tool used.

C. IPS: Prevents or blocks malicious traffic, but does not analyze existing packet captures.

D. Vulnerability scanner: Identifies vulnerabilities on systems/services; not used for packet capture review.

The scenario describes a cryptographic attack where the attacker (in this case, the student) uses a predefined list of commonly used passwords to try and unlock a secured PDF document. This technique is known as a Dictionary Attack.

According to the CEH v13 Official Courseware:

A Dictionary Attack is defined as “a method of breaking passwords by trying out a predefined list of words (dictionary) commonly used as passwords.”

Unlike a brute-force attack, which tries every possible character combination, a dictionary attack relies on known or likely password choices, which makes it faster but less exhaustive.

Dictionary attacks are commonly used against encrypted or password-protected files, login forms, and even hashes.

Relevant distinctions from other options:

A. Man-in-the-middle attack involves intercepting communication between two parties and is unrelated to offline password cracking.

B. Brute-force attack tries all possible character combinations, not just a list of known or common passwords.

D. Session hijacking involves taking over a user session and is unrelated to document password cracking.

Reference – CEH v13 Official Study Materials:

Module 20: Cryptography

Section: "Cryptanalysis Techniques"

Subsection: "Dictionary Attack vs. Brute-force Attack"

CEH v13 eBook or Study Guide — look for Table: “Types of Password Attacks” under “Cryptography Attack Vectors”

This exact technique is illustrated in CEH v13 labs involving John the Ripper, Hydra, and password recovery tools.

Email spoofing is the fabrication of an email header in the hopes of duping the recipient into thinking the email originated from someone or somewhere other than the intended source. Because core email protocols do not have a built-in method of authentication, it is common for spam and phishing emails to use said spoofing to trick the recipient into trusting the origin of the message.

The ultimate goal of email spoofing is to get recipients to open, and possibly even respond to, a solicitation. Although the spoofed messages are usually just a nuisance requiring little action besides removal, the more malicious varieties can cause significant problems and sometimes pose a real security threat.

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The most effective attack method for the penetration tester to exploit these vulnerabilities and attempt unauthorized access would be to execute a Brute Force attack, leveraging the lack of account lockout policy and the verbose error messages to guess the correct credentials. A Brute Force attack is a hacking method that uses trial and error to crack passwords, login credentials, or encryption keys. It is a simple yet reliable tactic for gaining unauthorized access to individual accounts and organizations’ systems and networks1. In this scenario, the tester can take advantage of the fact that the application does not lock out users after multiple failed login attempts, which means the tester can try as many combinations as possible without being blocked. The tester can also use the detailed error messages that disclose whether the username or password entered is incorrect, which can help narrow down the search space and reduce the number of guesses needed. For example, if the tester enters a wrong username and a wrong password, and the application responds with “Invalid username”, the tester can eliminate that username from the list of candidates and focus on finding the correct one. Similarly, if the tester enters a correct username and a wrong password, and the application responds with “Invalid password”, the tester can confirm that username and focus on finding the correct password. By using automated tools or scripts, the tester can perform a Brute Force attack faster and more efficiently.

The other options are not as effective or feasible as option A for the following reasons:

B. The tester could exploit a potential SQL Injection vulnerability to manipulate the application’s database: This option is not feasible because there is no indication that the application is vulnerable to SQL Injection, which is a web security vulnerability that allows an attacker to interfere with the queries that an application makes to its database2. The application uses form-based authentication, which does not necessarily involve SQL queries, and the error messages do not reveal any SQL syntax or structure. Moreover, even if the application was vulnerable to SQL Injection, the tester would need to craft a malicious SQL query that can bypass the authentication mechanism and grant access to the application, which may not be possible or easy depending on the database design and configuration.

C. The tester could launch a Cross-Site Scripting (XSS) attack to steal authenticated session cookies, potentially bypassing the clickjacking protection: This option is not effective because there is no evidence that the application is vulnerable to XSS, which is a web security vulnerability that allows an attacker to compromise the interactions that users have with a vulnerable application by injecting malicious scripts3. The application uses HTTP headers to prevent clickjacking attacks, which are a type of attack that tricks a user into clicking on a hidden or disguised element on a web page4. However, this does not imply that the application is vulnerable to XSS, which requires a different type of injection point and payload. Moreover, even if the application was vulnerable to XSS, the tester would need to find a way to deliver the malicious script to a legitimate user who is already authenticated, and then capture the stolen session cookies from the user’s browser, which may not be feasible or easy depending on the application’s design and security measures.

D. The tester could execute a Man-in-the-Middle (MitM) attack to intercept and modify the HTTP headers for a Clickjacking attack: This option is not feasible because a MitM attack is a type of attack that requires the attacker to insert themselves between two parties who believe that they are directly communicating with each other, and then relay or alter the communications between them5. In this scenario, the tester would need to intercept the HTTP traffic between the user and the application, and then modify the HTTP headers to remove or weaken the clickjacking protection. However, this would require the tester to have access to the network infrastructure or the user’s device, which may not be possible or easy depending on the network security and encryption. Moreover, even if the tester could perform a MitM attack, the tester would still need to trick the user into clicking on a malicious element on a web page, which may not be possible or easy depending on the user’s awareness and behavior.

In this attack KRACK is an acronym for Key Reinstallation Attack. KRACK may be a severe replay attack on Wi-Fi Protected Access protocol (WPA2), which secures your Wi-Fi connection. Hackers use KRACK to take advantage of a vulnerability in WPA2. When in close range of a possible victim, attackers can access and skim encrypted data using KRACK.

How KRACK Works

Your Wi-Fi client uses a four-way handshake when attempting to attach to a protected network. The handshake confirms that both the client — your smartphone, laptop, et cetera — and therefore the access point share the right credentials, usually a password for the network. This establishes the Pairwise passkey (PMK), which allows for encoding .

Overall, this handshake procedure allows for quick logins and connections and sets up a replacement encryption key with each connection. this is often what keeps data secure on Wi-Fi connections, and every one protected Wi-Fi connections use the four-way handshake for security. This protocol is that the reason users are encouraged to use private or credential-protected Wi-Fi instead of public connections.

KRACK affects the third step of the handshake, allowing the attacker to control and replay the WPA2 encryption key to trick it into installing a key already in use. When the key’s reinstalled, other parameters related to it — the incremental transmit packet number called the nonce and therefore the replay counter — are set to their original values.

Rather than move to the fourth step within the four-way handshake, nonce resets still replay transmissions of the third step. This sets up the encryption protocol for attack, and counting on how the attackers replay the third-step transmissions, they will take down Wi-Fi security.

Why KRACK may be a Threat

Think of all the devices you employ that believe Wi-Fi. it isn’t almost laptops and smartphones; numerous smart devices now structure the web of Things (IoT). due to the vulnerability in WPA2, everything connected to Wi-Fi is in danger of being hacked or hijacked.

Attackers using KRACK can gain access to usernames and passwords also as data stored on devices. Hackers can read emails and consider photos of transmitted data then use that information to blackmail users or sell it on the Dark Web.

Theft of stored data requires more steps, like an HTTP content injection to load malware into the system. Hackers could conceivably take hold of any device used thereon Wi-Fi connection. Because the attacks require hackers to be on the brink of the target, these internet security threats could also cause physical security threats.

On the opposite hand, the necessity to be in close proximity is that the only excellent news associated with KRACK, as meaning a widespread attack would be extremely difficult.

Victims are specifically targeted. However, there are concerns that a experienced attacker could develop the talents to use HTTP content injection to load malware onto websites to make a more widespread affect.

Everyone is in danger from KRACK vulnerability. Patches are available for Windows and iOS devices, but a released patch for Android devices is currently in question (November 2017). There are issues with the discharge , and lots of question if all versions and devices are covered.

The real problem is with routers and IoT devices. These devices aren’t updated as regularly as computer operating systems, and for several devices, security flaws got to be addressed on the manufacturing side. New devices should address KRACK, but the devices you have already got in your home probably aren’t protected.

The best protection against KRACK is to make sure any device connected to Wi-Fi is patched and updated with the newest firmware. that has checking together with your router’s manufacturer periodically to ascertain if patches are available.

The safest connection option may be a private VPN, especially when publicly spaces. If you would like a VPN for private use, avoid free options, as they need their own security problems and there’ll even be issues with HTTPs. Use a paid service offered by a trusted vendor like Kaspersky. Also, more modern networks use WPA3 for better security.

Avoid using public Wi-Fi, albeit it’s password protection. That password is out there to almost anyone, which reduces the safety level considerably.

All the widespread implications of KRACK and therefore the WPA2 vulnerability aren’t yet clear. what’s certain is that everybody who uses Wi-Fi is in danger and wishes to require precautions to guard their data and devices.

A null user is a special connection made to a Windows system without providing a username or password. In older versions of Windows (NT, 2000, XP), null sessions could be used to anonymously connect to IPC$ share and enumerate:

Users

Groups

Shares

Policies

From CEH v13 Courseware:

Module 4: Enumeration → Null Sessions

CEH v13 Study Guide states:

“Null users are unauthenticated sessions used to access certain system resources without credentials. These are commonly used in enumeration attacks.”

Comprehensive and Detailed Explanation:

This is a classic example of social engineering. When a system is well-secured technically, attackers often turn to exploiting human vulnerabilities — such as:

Talking to employees and gaining their trust

Bribing disgruntled or low-level staff

Gaining physical access or insider information through manipulation

From CEH v13 Courseware:

Module 7: Social Engineering

Incorrect Options:

A: Zero-days are rare and expensive; not always feasible.

C: DDoS is disruptive, not data-oriented.

D: MiTM is a complex network-based attack, unlikely effective against a hardened internal mainframe.

LM hashes are split into two 16-character halves (each representing 7-character blocks). If the original password is less than 8 characters, the second half of the LM hash will always be a constant:

"AAD3B435B51404EE"

This known value is used to pad the second half of the password, and it signals that the original password was 7 characters or fewer.

In the options:

B. 44EFCE164AB921CQAAD3B435B51404EE ← ends with AAD3B435B51404EE → < 8 chars

E. B757BF5C0D87772FAAD3B435B51404EE ← also ends with AAD3B435B51404EE → < 8 chars

From CEH v13 Official Courseware:

Module 6: Malware Threats → LM Hash Weaknesses