PDF 312-50v13 Study Guide

WEP encryption is an outdated and insecure method of protecting wireless networks from unauthorized access and eavesdropping. WEP uses a static key that can be easily cracked by various tools and techniques, such as capturing the initialization vectors, brute-forcing the key, or exploiting the weak key scheduling algorithm1. Therefore, you should recommend a more secure encryption method to enhance the security of the company’s wireless network.

One of the most suitable replacements for WEP encryption is WPA2-PSK with AES encryption. WPA2 stands for Wi-Fi Protected Access 2, which is a security standard that improves upon the previous WPA standard. WPA2 uses a robust encryption algorithm called AES, which stands for Advanced Encryption Standard. AES is a block cipher that uses a 128-bit key and is considered to be very secure and resistant to attacks2.

WPA2-PSK stands for WPA2 Pre-Shared Key, which is a mode of WPA2 that uses a passphrase or a password to generate the encryption key. The passphrase or password must be entered by the users who want to connect to the wireless network. The key is then derived from the passphrase or password using a function called PBKDF2, which stands for Password-Based Key Derivation Function 2. PBKDF2 adds a salt and a number of iterations to the passphrase or password to make it harder to crack3.

WPA2-PSK with AES encryption offers several advantages over WEP encryption, such as:

It uses a dynamic key that changes with each session, instead of a static key that remains the same.

It uses a stronger encryption algorithm that is more difficult to break, instead of a weaker encryption algorithm that is more vulnerable to attacks.

It uses a longer key that provides more security, instead of a shorter key that provides less security.

It uses a more secure key derivation function that adds complexity and randomness, instead of a simple key generation function that is predictable and flawed.

Therefore, you should recommend WPA2-PSK with AES encryption as a suitable replacement to enhance the security of the company’s wireless network.

In CEH v13 Module 01: Information Security Controls, the Remote Access Policy is defined as the guideline that governs:

Which remote access methods (VPNs, modems, RDP, etc.) are permitted.

Requirements for authentication and encryption.

Who is authorized to use them and under what conditions.

In This Case:

The use of a dial-out modem is considered a remote access method, especially if it bypasses the corporate firewall.

The analyst needs to check whether such remote access is permitted, and under what security controls.

DNS cache snooping is an enumeration technique where the attacker queries a DNS server to check whether a specific domain has been recently resolved by the server (i.e., it exists in the cache). If a positive response is received with low latency, it indicates that the domain was visited recently.

Key points:

Used to infer user browsing habits or visited domains.

Helps attackers identify user interests or potential targets.

Incorrect Options:

A. DNS zone walking is used to list all domain names in a DNS zone (with misconfigured DNS servers), not for cached record inspection.

C. DNSSEC zone walking applies only when DNSSEC is misconfigured.

D. DNS cache poisoning is a manipulation technique, not a passive enumeration method.

Reference – CEH v13 Official Courseware:

Module 04: Enumeration

Section: “DNS Enumeration”

Subsection: “DNS Cache Snooping and Timing Analysis”

Tool Reference: dig, nslookup

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Employing a tool like Sublist3r, which is designed to enumerate the subdomains of websites using OSINT, would be the most effective method to accomplish this goal. This option works as follows:

Sublist3r is a python tool designed to enumerate subdomains of websites using OSINT (Open Source Intelligence). It helps penetration testers and bug hunters collect and gather subdomains for the domain they are targeting. Sublist3r enumerates subdomains using many search engines such as Google, Yahoo, Bing, Baidu, and Ask. Sublist3r also enumerates subdomains using Netcraft, Virustotal, ThreatCrowd, DNSdumpster, and ReverseDNS. Subbrute was integrated with Sublist3r to increase the possibility of finding more subdomains using bruteforce with an improved wordlist1.

By using Sublist3r, the tester can quickly and efficiently discover the subdomains of the target organization’s website, which can provide valuable information about the network structure, the services offered, the potential vulnerabilities, and the attack surface. Sublist3r can also be used to perform passive reconnaissance, which does not send any packets to the target domain, and thus avoids detection by the target organization12.

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

B. Analyzing Linkedin profiles to find employees of the target company and their job titles: This option is not relevant because it does not address the subdomain enumeration task, but the social engineering task. Linkedin is a social networking platform that allows users to create and share their professional profiles, which may include their name, job title, company, skills, education, and contacts. By analyzing Linkedin profiles, the tester may be able to find employees of the target company and their job titles, which can be useful for crafting phishing emails, impersonating employees, or exploiting human weaknesses. However, this option does not help to discover the subdomains of the target organization’s website, which is the goal of this scenario3.

C. Utilizing the Harvester tool to extract email addresses related to the target domain using a search engine like Google or Bing: This option is not sufficient because it does not provide a comprehensive list of subdomains, but only a partial list based on email addresses. The Harvester is a tool that can extract email addresses, subdomains, hosts, employee names, open ports, and banners from different public sources, such as search engines, PGP key servers, and SHODAN computer database. By using the Harvester, the tester may be able to extract some email addresses related to the target domain, which can reveal some subdomains, such as mail.target.com or support.target.com. However, this option does not guarantee to find all the subdomains of the target organization’s website, as some subdomains may not have any email addresses associated with them, or may not be indexed by the search engines4.

D. Using a people search service, such as Spokeo or Intelius, to gather information about the employees of the target organization: This option is not applicable because it does not address the subdomain enumeration task, but the personal information gathering task. Spokeo and Intelius are people search services that can provide various information about individuals, such as their name, address, phone number, email, social media, criminal records, and financial history. By using these services, the tester may be able to gather information about the employees of the target organization, which can be useful for performing background checks, identity theft, or blackmail. However, this option does not help to discover the subdomains of the target organization’s website, which is the goal of this scenario56.