ECCouncil 312-50v13 - Certified Ethical Hacker Exam (CEHv13)

Comprehensive and Detailed Explanation:

The code shown in the image is indicative of a Cross-Site Scripting (XSS) attack, where malicious JavaScript is injected into a web page via user input. In this case, the attacker includes:

%3Cscript%20src=...%3E — URL-encoded JavaScript tag to load a malicious script from an external source.

If the web application echoes this input back without sanitization, the script will execute in the context of the victim’s browser.

This allows the attacker to:

Steal cookies/session tokens

Perform actions on behalf of the victim

Redirect the victim to malicious websites

From CEH v13 Courseware:

Module 10: Web Application Hacking → Cross-Site Scripting (XSS)

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)

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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.

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.

MAC flooding is a Layer 2 attack in which an attacker sends a large number of fake MAC addresses to a switch, filling up its CAM (Content Addressable Memory) table. Once the table is full:

The switch enters “fail-open” mode and broadcasts traffic to all ports

The attacker can then sniff sensitive traffic

This attack effectively turns a switch into a hub, facilitating data sniffing.

Incorrect Options:

A. Evil twin is a wireless attack using rogue access points.

B. DNS cache flooding corrupts DNS entries, unrelated to Ethernet.

D. DDoS attacks are about overwhelming systems/services, not Layer 2 memory overflows.

Reference – CEH v13 Official Courseware:

Module 11: Sniffing

Section: “Switch Port Stealing and MAC Flooding”

Subsection: “Layer 2 Attacks and CAM Table Poisoning”

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A pharming attacker tries to send a web site’s traffic to a faux website controlled by the offender, typically for the aim of collection sensitive data from victims or putting in malware on their machines. Attacker tend to specialize in making look-alike ecommerce and digital banking websites to reap credentials and payment card data.

Though they share similar goals, pharming uses a special technique from phishing. “Pharming attacker are targeted on manipulating a system, instead of tricking people into reaching to a dangerous web site,” explains David Emm, principal security man of science at Kaspersky. “When either a phishing or pharming attacker is completed by a criminal, they need a similar driving issue to induce victims onto a corrupt location, however the mechanisms during which this is often undertaken are completely different.”

The TCP three-way handshake is the foundational mechanism used to establish a reliable connection between two devices. The sequence is as follows:

The client sends a SYN (synchronize) packet to the server to initiate the connection.

The server replies with a SYN-ACK (synchronize-acknowledge) packet.

The client sends an ACK (acknowledge) packet back to the server.

Therefore, the connection starts with a SYN packet from the client.

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.

https://en.wikipedia.org/wiki/Nikto_(vulnerability_scanner)

Nikto is a free software command-line vulnerability scanner that scans web servers for dangerous files/CGIs, outdated server software, and other problems. It performs generic and server types specific checks. It also captures and prints any cookies received. The Nikto code itself is free software, but the data files it uses to drive the program are not.

According to CEH v13 Module 06: Malware Threats, USB Dumper is a tool often used in insider threat or data exfiltration scenarios, where it automatically and silently copies files from any USB drive connected to a system.

It operates in the background and requires no user interaction once installed.

Files are copied from the USB to a pre-configured local directory.

USB Dumper is used in various penetration testing scenarios to simulate data theft using physical access.

Option Clarifications:

A. USB Grabber: Not a recognized standard tool in CEH or industry.

B. USB Snoopy: Used for monitoring USB communications (not silent copying).

C. USB Sniffer: Used for sniffing USB device communication traffic, not file theft.

D. USB Dumper: Correct tool for silently copying USB content.

WHOIS is an Internet service that allows users to query domain name registries to retrieve information about registered domain names. It includes data such as:

Registrant’s name and contact information

Domain creation and expiration dates

Registrar details and name servers

WHOIS is often used during the reconnaissance phase in penetration testing.

Reference – CEH v13 Official Study Guide:

Module 2: Footprinting and Reconnaissance

Quote:

“WHOIS databases provide public domain registration details including contact names, email addresses, and registrar information. This is useful for initial reconnaissance.”

Incorrect Options:

B. CAPTCHA is used to distinguish human users from bots.

C. IANA oversees global IP address allocation and DNS root zone management.

D. IETF is responsible for internet standards, not registrant databases.

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The attacker has most likely used RST hijacking, which is a type of network-level session hijacking technique that exploits the TCP reset (RST) mechanism. TCP reset is a way of terminating an established TCP connection by sending a packet with the RST flag set, indicating that the sender does not want to continue the communication. RST hijacking involves sending a forged RST packet to one or both ends of a TCP connection, using a spoofed source IP address and a guessed acknowledgment number, to trick them into believing that the other end has closed the connection. As a result, the victim’s connection is reset and the attacker can take over the session or launch a denial-of-service attack12.

The other options are not correct for the following reasons:

A. TCP/IP hijacking: This option is a general term that refers to any type of network-level session hijacking technique that targets TCP/IP connections. RST hijacking is a specific type of TCP/IP hijacking, but not the only one. Other types of TCP/IP hijacking include SYN hijacking, source routing, and sequence prediction3.

B. UDP hijacking: This option is not applicable because UDP is a connectionless protocol that does not use TCP reset mechanism. UDP hijacking is a type of network-level session hijacking technique that targets UDP connections, such as DNS or VoIP. UDP hijacking involves intercepting and modifying UDP packets to redirect or manipulate the communication between the sender and the receiver4.

D. Blind hijacking: This option is not accurate because blind hijacking is a type of network-level session hijacking technique that does not require injecting RST packets. Blind hijacking involves guessing the sequence and acknowledgment numbers of a TCP connection without being able to see the responses from the target. Blind hijacking can be used to inject malicious data or commands into an active TCP session, but not to reset the connection5.

Analyze Web Applications: Identify Files and Directories - enumerate applications, as well as hidden directories and files of the web application hosted on the web server. Tools such as ☆Gobuster is directory scanner that allows attackers to perform fast-paced enumeration of hidden files and directories of a target web application. # gobuster -u -w common.txt (wordlist) (P.1849/1833)

MX (Mail Exchange) records in DNS define the mail servers responsible for receiving email for a domain. Each MX record has a priority value.

Important concept:

A lower number indicates a higher priority.

Email servers attempt delivery to the mail server with the lowest priority first.

For example:

If MX records are:

10 mail1.example.com

20 mail2.example.com

Then mail1 will be tried first. If it fails, mail2 will be used.

So the statement “MX record priority increases as the number increases” is false.

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