ECCouncil 312-50v13 - Certified Ethical Hacker Exam (CEH v13 AI)

CEH describes FIN scans as stealthy scans that send packets with the FIN flag without initiating a TCP handshake. According to TCP RFC behavior, closed ports respond with RST packets while open ports ignore the probe, producing no response. This allows enumeration of port states while evading IDS systems that typically monitor SYN-based scans.

The CEH Footprinting and Reconnaissance module highlights Google Alerts as a key passive reconnaissance tool for monitoring changes in web content, news, and online mentions.

Option B is correct.

Option A is active engagement.

Option C aids anonymity but not monitoring.

Option D is illegal and unethical.

CEH strongly promotes automated alerting for competitive intelligence.

The correct answer is D. This message shows classic social engineering and smishing indicators: it arrives by mobile text, claims urgency with a “vital transaction,” impersonates a trusted organization, and asks Bob to contact a free public email address. A legitimate bank or financial institution would normally use an official corporate domain, not a generic @yahoo.com mailbox. Option A is weak because not knowing Scott alone does not prove fraud; the stronger evidence is the suspicious sender identity and unofficial contact channel. Option B is incorrect because the message only claims to represent a respectable organization; attackers often impersonate trusted brands. Option C is unsafe because replying to the provided address validates Bob as a target and may continue the scam. CEH social engineering guidance emphasizes verifying requests through trusted, independent channels and recognizing phishing/smishing attempts that exploit urgency, authority, and user trust. Therefore, the best answer is D.

The correct answer is Checks for outdated versions of over 1,250 servers. In CEH vulnerability assessment coverage, Nessus Essentials is presented as a vulnerability scanning solution that can assess a wide variety of technologies, including operating systems, web servers, databases, network devices, and virtualized environments. Its core role is identifying weaknesses, missing patches, insecure configurations, and exposure conditions across supported platforms. The option about checking outdated versions across a very broad range of server technologies best reflects that scanner-oriented capability. Patch management is not the primary function of Nessus Essentials, because it identifies vulnerabilities rather than directly managing patch deployment. Agent-based detection may be used in some security products, but that is not the defining capability highlighted in this CEH-style framing. High-speed asset discovery is a feature associated more strongly with specialized discovery platforms, whereas Nessus is centered on vulnerability enumeration and assessment. CEH study material emphasizes understanding the purpose of common security tools, and Nessus is generally classified as a scanner that detects outdated software versions and known vulnerabilities so remediation can be prioritized across the environment. That is why option B is the most accurate fit.

The described activity is most consistent with a Remote Access Trojan (RAT). A RAT is designed to provide an attacker with remote, covert, and persistent control over a compromised system. The scenario explicitly states that after the attachment is opened, the attacker gains “full access to the workstation” and then monitors emails, keystrokes, and local files over an extended period without alerting the user. That combination—remote control plus long-term stealthy monitoring—fits a RAT’s typical capabilities, which often include keylogging, file browsing/exfiltration, screen capture, command execution, and maintaining persistence.

Although spyware can also monitor keystrokes and user activity, spyware is typically described as focusing on surveillance and data collection rather than providing broad interactive remote administration. The scenario emphasizes “full access” and ongoing control, which is more characteristic of a RAT than spyware alone. In many real-world cases, RATs include spyware-like features; however, when the question asks which malware type best matches full remote control and stealth monitoring, RAT is the strongest match.

Why the other options are less suitable:

Botnet (B) refers to a network of infected systems (bots) controlled as a group, often for DDoS, spam, or distributed operations. The scenario focuses on a single workstation being remotely controlled and monitored.

Adware (C) focuses on delivering advertisements and tracking for marketing purposes; it does not align with covert full access and credential monitoring.

Spyware (D) overlaps on surveillance, but it does not inherently imply comprehensive remote administration and control the way a RAT does.

Therefore, the most likely malware type is A. Remote Access Trojan (RAT).

In CEH v13 Information Security and Ethical Hacking Overview, a penetration tester is defined as a trusted, authorized security professional hired to simulate real-world attacks in order to identify and exploit vulnerabilities with explicit permission.

The primary objectives of a penetration tester are:

Identify weaknesses in systems, networks, and applications

Demonstrate real-world impact of vulnerabilities

Help organizations improve their security posture

Unlike malicious hackers (Option A) or malware authors (Options B and D), penetration testers operate under strict legal and ethical guidelines, following scopes of engagement and reporting findings responsibly.

CEH v13 emphasizes that penetration testing is proactive defense, not crime. Therefore, Option C accurately defines the role.

The correct answer is A. LDAP Injection.

The scenario describes malicious input being inserted into directory-based search logic used to validate identities. LDAP is commonly used for centralized directory authentication and account lookups. When user input is embedded directly into LDAP filters without proper validation, an attacker can alter the filter logic using operators, wildcards, and special LDAP syntax.

CEH-aligned material states that LDAP injection takes advantage of non-validated input and that an attacker may access information by using an LDAP filter to search the directory database . Another CEH exam reference explains that LDAP injection exploits applications that construct LDAP statements based on user input and pass that input directly into LDAP queries .

Option B. OS Command Injection is incorrect because the scenario does not involve operating system commands.

Option C. SQL Injection is incorrect because the backend lookup is directory-based, not relational database SQL.

Option D. XPath Injection is incorrect because XPath injection targets XML query expressions, not LDAP directory filters.

Therefore, the best answer is A. LDAP Injection.

The correct answer is A. Service Version Discovery because the objective is to identify the software release/version running on internet-facing services by analyzing network responses and application output—without authenticating or establishing full sessions. In CEH-aligned reconnaissance methodology, service/version discovery (often called version detection or banner grabbing) focuses on determining what service is running (e.g., HTTP server, SSH daemon, SMTP server) and which version/build it is (e.g., Apache/Nginx version, OpenSSH version, application framework release). This information directly supports “prioritizing patch baselines” because patch urgency depends heavily on exact product versions: knowing the version helps map exposure to known vulnerabilities and identify outdated builds.

The prompt’s wording “analyze network-level responses and capture application output” is consistent with techniques such as banner grabbing, protocol negotiation, and response fingerprinting. Many services disclose identifying strings in headers, greetings, error pages, TLS certificates, or protocol handshakes. Even when banners are minimized, subtle differences in responses can still indicate versions or at least narrow the product family. This is typically done externally and does not require credentials, matching the constraint “without logging in or establishing full sessions.”

Why the other options are less accurate: Port scanning identifies which ports are open and which services may be present, but it does not necessarily determine precise software releases. OS discovery (OS fingerprinting) aims to infer the operating system and sometimes kernel family from packet characteristics; it is helpful but the task emphasizes “software release” and “application output,” which aligns more with service version detection than OS detection. Vulnerability scanning goes further by testing for known weaknesses and misconfigurations; while it may include version detection, the question asks for the technique that best fits the stated objective—determining the underlying service/software release from network/application responses—making service version discovery the most direct match.

Therefore, the technique is Service Version Discovery.

The correct answer is B because scheduled tasks are commonly abused for persistence. In system hacking and post-exploitation phases, persistence means maintaining access to a compromised system even after reboot, logoff, or temporary session loss. Attackers may abuse Windows Task Scheduler or Linux cron jobs to automatically run malware, scripts, callbacks, or backdoors at specific intervals, during startup, or when a user logs in. The retrieved guide material shows scheduled-task usage for recurring execution and also references persistence-focused modules such as post/windows/manage/persistence, which aligns with the CEH concept of maintaining access after compromise. Reconnaissance is information gathering before attack, sniffing captures network traffic, and DoS attempts to disrupt availability. Those do not specifically describe abusing scheduled tasks. Defensively, administrators should audit scheduled jobs, monitor task creation events, restrict task-creation privileges, and investigate unknown startup or recurring tasks.

The correct answer is D, BOLA, or Broken Object Level Authorization. This occurs when an API accepts an object identifier supplied by the user, such as an account ID, order ID, invoice ID, or user ID, but fails to verify whether the authenticated user is authorized to access that specific object. CEH web application hacking material describes this same weakness as an authorization flaw/insecure direct object reference: an application uses IDs to distinguish users, and an attacker changes an ID value in the request to access another user’s profile. CEH material also explains that unauthorized access to another user’s resources represents horizontal privilege escalation and that function-level access issues occur when the application does not check authorization before returning protected information. Mass assignment involves binding unexpected fields, XSS involves script injection, and SQLi involves malicious database queries. The key issue here is missing object-level authorization, so BOLA is the best answer.

Comprehensive and Detailed Explanation From CEH v13 Guide Topics:

The correct answer is D. Multipartite Virus. A multipartite virus is a sophisticated type of malware that infects multiple parts of a computer system simultaneously, most commonly the boot sector and executable files. Because it attacks more than one target, it can spread rapidly and is often more difficult to remove than single-vector viruses. Even if infected executable files are cleaned, the virus may remain active in the boot sector and reinfect the system during startup. Likewise, cleaning only the boot sector may leave infected files that can later reinfect the boot area.

Option A (Stealth Virus) is designed to hide its presence by manipulating operating system functions and returning false information to security tools. Option B (Polymorphic Virus) changes its code or signature each time it infects a system to evade detection by antivirus software. Option C (Macro Virus) primarily infects documents and applications that support macro languages, such as Microsoft Office files.

From a CEH malware analysis perspective, malware is often classified by its infection method, propagation technique, and concealment strategy. The defining characteristic of a multipartite virus is its ability to infect both the boot sector and executable files simultaneously, making D the correct answer.

This scenario most accurately represents repackaging legitimate apps. CEH mobile social engineering coverage explains that in a repackaging attack, an adversary takes a real application, modifies its internal code or structure to include malicious functionality, and redistributes it through a third-party marketplace. The important clues here are that the app appears visually and functionally identical to the legitimate version, yet sandboxing reveals additional outbound activity and binary comparison confirms structural differences from the official build. That pattern is stronger than merely publishing a look-alike malicious app, because the question indicates there are two versions of what is essentially the same application and the unofficial copy has been altered. Smishing involves fraudulent SMS messages and fake security applications typically masquerade as protective tools, neither of which matches this case. CEH warns that unofficial application stores are a common distribution point for repackaged mobile apps because attackers can embed spyware, adware, credential theft code, or other malicious logic into otherwise trusted software. The user often sees a familiar interface and therefore assumes the application is safe, making repackaging a highly effective mobile-based social engineering method.

The risk described is increased attack surface caused by unnecessary services and protocols running on a web server—specifically NetBIOS and SMB. The most direct hardening action to mitigate this is to block/disable unnecessary ports and protocols so they are not exposed to the network and cannot be abused by attackers. Option D captures that principle: reduce exposure by closing ports and restricting protocols that are not required for the server’s role.

A well-hardened web server should run only the services needed to deliver its intended web functionality (e.g., HTTP/HTTPS and necessary management interfaces under strict control). Services like SMB (commonly TCP 445/139) and NetBIOS (UDP 137/138, TCP 139) are not normally required for public-facing web hosting and are frequent targets for enumeration and exploitation. Leaving such services open can enable attackers to perform credential attacks, exploit legacy vulnerabilities, access shared resources, or pivot further into the environment. By blocking or disabling these ports at the host firewall and/or perimeter firewall, the organization reduces reachable attack paths and limits what an external attacker can interact with.

Why the other options are less direct:

Dedicated machine (A) can help separation of duties, but if unnecessary services still run, the attack surface remains.

Risk assessment for patching (B) is important, but it doesn’t immediately remove the exposure created by unneeded services.

Eliminating unnecessary files (C) addresses file-system exposure, not open network services like SMB/NetBIOS.

Because the problem is explicitly about unnecessary open services/protocols, the best mitigation is D. Block all unnecessary ports, ICMP traffic, and protocols (i.e., minimize exposed services).

This task describes passive reconnaissance using advanced search operators, a technique covered in CEH as search engine reconnaissance or Google dorking. The objective is to find potentially exposed documents on hidden services while avoiding direct interaction with forums or services. The most important element in the query is restricting results to hidden service domains using the site:onion operator. Any option that does not include site:onion is less suitable because it will return results from the public web rather than from .onion resources.

Option A is the strongest fit because it combines three high-value filters: filetype:pdf to focus on document artifacts that are commonly leaked or shared, intitle: " admin access " to target titles suggesting privileged access or administrative information, and site:onion to restrict the scope to hidden services. In CEH reporting and threat intelligence workflows, targeting high-signal keywords such as admin access, credentials, password list, or vpn access in document metadata is a practical way to identify likely leak sources without active engagement.

Option B lacks site:onion, so it fails the hidden-service requirement. Option C includes site:onion but the phrase secure login is more generic and may return many benign pages, reducing precision. Option D includes site:onion and filetype targeting, but user accounts is broader and less indicative of immediate access data than admin access. Therefore, A best supports efficient passive discovery of high-risk documents relevant to credential exposure on hidden services.

The correct answer is DNS Cache Poisoning. CEH network security material explains that cache poisoning occurs when a DNS server is tricked into storing fraudulent name-to-IP mappings in its cache. Once the poisoned entry is cached, many users querying that DNS service receive the same false resolution until the cache is flushed, expires, or the service is restarted. That maps directly to the scenario: multiple internal clients receive the same incorrect IP address for a legitimate domain, and the issue disappears after the organization’s name resolution service is restarted. Intranet DNS spoofing typically involves local interception and very fast forged replies on a LAN, while proxy server DNS poisoning changes browser-side proxy behavior, and internet DNS spoofing usually involves altering a host’s DNS configuration or redirecting it to a malicious resolver. The persistence across many users and the recovery after DNS service restart are the most important clues, because they indicate poisoned cached records on the resolver itself rather than isolated endpoint tampering. CEH guidance highlights that DNS cache poisoning can silently redirect users to counterfeit systems while appearing to resolve legitimate domain names normally.