Free ECCouncil 312-50v13 Practice Exam with Questions & Answers | Set: 2

This scenario describes a Slowloris attack, a classic application-layer DoS attack covered in CEH v13 Network and Perimeter Hacking. Slowloris works by opening many HTTP connections and sending data very slowly, preventing the server from closing the connections.

Because the connections appear legitimate, the server keeps them open, eventually exhausting its connection pool. This causes legitimate users to experience timeouts and service unavailability—exactly as described.

ICMP and UDP floods consume bandwidth, which was ruled out. Fragmentation attacks target packet handling, not application-layer sessions.

CEH v13 highlights Slowloris as particularly dangerous because it requires minimal bandwidth and bypasses many traditional DoS defenses. Therefore, Option A is correct.

The correct answer is D, ciphertext-only attack, because the attackers possess only encrypted data and have neither the encryption key nor any confirmed samples of the original plaintext. In CEH-aligned cryptography concepts, cryptanalytic attacks are categorized by what information and capabilities the attacker has. A ciphertext-only attack is the most constrained model: the attacker attempts to infer the plaintext or key by analyzing ciphertext alone, often leveraging statistical properties, repetitions, formatting assumptions, and structural patterns that may leak information when encryption is misused.

The scenario highlights that the attacker “examines encrypted outputs in bulk” to detect “structural or statistical patterns.” That wording maps directly to ciphertext-only analysis: looking for patterns caused by weak modes of operation, poor IV/nonce handling, deterministic encryption, repeated blocks (common in ECB mode), predictable headers, or consistent record templates. With block ciphers, large datasets increase the chance that repeated plaintext blocks produce repeated ciphertext blocks if the system uses an unsafe mode or reuses IVs, allowing an attacker to correlate records, identify fields, or sometimes recover content when combined with protocol or file-format knowledge.

The other options require more attacker capability than the prompt provides. Known-plaintext attacks require some plaintext-ciphertext pairs. Chosen-plaintext attacks require the ability to encrypt attacker-chosen inputs. Chosen-ciphertext attacks require a decryption oracle or the ability to submit ciphertext for decryption. Since none of those are present here, Emma should evaluate ciphertext-only exposure and specifically validate the cipher mode, IV/nonce uniqueness, padding behavior, and whether encryption is semantically secure for stored patient records.

yes do please

CEH defines spyware as malware designed to covertly observe user behavior and transmit sensitive information to attackers without the victim’s knowledge. Spyware commonly records keystrokes, browser activity, form submissions, application usage, and other personally identifiable information. CEH highlights that spyware often operates silently and may disguise itself as legitimate software, making detection difficult. Unlike rootkits—which hide processes and files—or worms that self-replicate, spyware focuses exclusively on monitoring and data exfiltration. It is frequently installed through phishing, drive-by downloads, browser vulnerabilities, or malicious installers. Spyware can serve as a stepping stone for further system compromise by providing attackers with credentials for privilege escalation, lateral movement, or financial theft. CEH emphasizes the need for endpoint hardening, updated anti-malware engines, and behavioral analysis tools to detect such stealthy monitoring programs.

CEH notes that cloud IAM misconfigurations can unintentionally grant broad access. If any authenticated cloud account is permitted read/write access, attackers can simply authenticate with their own cloud identity and directly interact with the misconfigured storage buckets, enabling data exfiltration or manipulation.

CEH v13 classifies application-layer DoS attacks as the most difficult to detect and mitigate. A distributed SQL injection-based DoS exploits database query processing by overwhelming backend systems with malicious but syntactically valid requests.

Unlike volumetric attacks, this method generates low-bandwidth, high-impact traffic that appears legitimate. Traditional DDoS protections often fail to identify such traffic, especially when it targets authenticated services like online banking.

UDP floods, Smurf attacks, and ICMP-based attacks are well-known and more easily mitigated with rate limiting and filtering. Zero-day exploits cause service disruption but are not primarily DoS techniques.

CEH v13 highlights that application-layer DoS attacks blend seamlessly with normal traffic patterns, making them exceptionally challenging. Thus, option A is correct.

The correct answer is B. MODBUS.

The defining indicators are TCP port 502, reading coil status, and writing register values. These are classic characteristics of Modbus/TCP, a widely used industrial control protocol.

CEH-aligned OT/ICS material identifies Modbus as a protocol used in industrial control systems and shows Modbus reconnaissance and interaction using port 502. It also describes Modbus function-code operations such as writing a single coil and reading input registers .

Option A. IEC 60870-5-104 is incorrect because IEC 104 is commonly associated with TCP port 2404, not port 502.

Option C. DNP3 is incorrect because DNP3 commonly uses TCP/UDP port 20000.

Option D. OPC UA is incorrect because OPC UA is not identified by Modbus coil/register operations on TCP 502.

Therefore, the best answer is B. MODBUS.

The correct answer is B. ARP Spoofing because the described outcome—silently redirecting traffic between two hosts through the attacker’s machine on a LAN without changing switch configurations—is the classic effect of ARP poisoning (also called ARP spoofing). In CEH-aligned network sniffing and man-in-the-middle (MITM) techniques, ARP spoofing works by sending forged ARP replies onto the local network so that a victim host associates the attacker’s MAC address with the IP address of a legitimate system (commonly the default gateway or another target host). Once the victim’s ARP cache is poisoned, frames intended for the real destination are instead sent to the attacker, who can then forward them to the legitimate host to maintain connectivity while inspecting or altering the traffic.

The scenario states David “injects crafted messages” and then “all traffic between a finance workstation and the authentication server is silently routed through his system.” That behavior strongly indicates ARP spoofing performed in both directions: poisoning the workstation to believe the attacker is the authentication server (or gateway) and poisoning the server to believe the attacker is the workstation (or gateway). This enables a transparent MITM position where credentials can be observed—especially if protocols are unencrypted or if the attacker can downgrade or strip protections. The fact that “no proxy or VPN is in use” supports the idea that the redirection is happening at Layer 2/Layer 3 on the local segment rather than via an explicit application-level proxy.

Why the other options are less accurate: Switch port stealing targets switch CAM tables to redirect frames, but it is less directly described than ARP cache poisoning between two IP endpoints. An STP attack manipulates spanning tree to become the root bridge and can influence paths, but it is a different control-plane attack and usually affects broader Layer 2 topology. IRDP spoofing involves ICMP Router Discovery Protocol to advertise a rogue router, but the scenario fits the much more common and direct MITM sniffing technique on a switched LAN: ARP spoofing.

Therefore, David most likely used ARP spoofing.

The correct answer is F because the Windows Administrator account is identified by its RID value, not merely by the visible username. In Windows enumeration, a Security Identifier, or SID, uniquely identifies user, group, and computer accounts. The last portion of the SID is the Relative Identifier, or RID. CEH-aligned material explains that Windows uses SIDs and RIDs to track account rights and permissions, and the RID value 500 identifies the built-in Administrator account. The Guest account normally uses RID 501, while standard created users usually begin at 1000 and increment upward. Therefore, when SIDExtractor displays multiple users, the account whose SID ends in -500 is the system administrator account, even if the Administrator account has been renamed. Enumeration tools such as sid2user and user2sid are used to map usernames to SIDs and SIDs to usernames. In this question, John corresponds to the administrator RID, so option F is correct.

Thomas is most likely using Follow TCP Stream. This Wireshark feature reconstructs the bidirectional application data carried over a TCP connection by reassembling packets in sequence into a readable conversation view. When traffic is unencrypted HTTP, the reassembled stream can reveal full request/response content, including URLs, headers, form parameters, and—critically in this scenario—usernames and passwords transmitted in clear text (for example, within POST body parameters).

The scenario’s language is a direct match: “reconstruct entire conversations between browsers and the server” and “reassembles packet data into a readable stream.” That is exactly what Follow TCP Stream does: it groups packets that belong to the same TCP session and displays the payload as contiguous data, making it far easier than manually inspecting individual packets. This is commonly used during assessments and investigations to understand what data was exchanged, validate whether sensitive data is exposed, and confirm whether protections like TLS are properly applied.

Why the other options are not correct:

Filtering by IP Address (A) helps narrow the packet list to specific hosts but does not reconstruct conversations.

Display Filtering by Protocol (B) can isolate HTTP packets but still leaves the analyst to interpret individual packets without full reassembly.

Monitoring the Specific Ports (C) similarly narrows traffic (e.g., TCP/80 for HTTP) but does not present a reassembled readable session.

Because the goal is quick, readable reconstruction of HTTP login sessions over TCP, the correct answer is D. Follow TCP Stream.

Comprehensive Explanation from CEH v13 Courseware:

CEH v13 explains that TOCTOU (Time-of-Check Time-of-Use) vulnerabilities arise when a system checks a condition (such as file permissions) and then later uses the resource based on that assumption. If there is even a tiny gap between the validation and the actual use, attackers can exploit this race condition by replacing or modifying the resource after validation but before execution. This is common in file-handling operations involving temporary files, symbolic links, or shared directories. CEH emphasizes that TOCTOU attacks often lead to privilege escalation, unauthorized execution, or tampering with data because the system trusts the earlier validation step. The attacker swaps the file at precisely the right moment, taking advantage of a race window. The other options—certificate validation, integer overflow, and null pointer dereference—do not involve timing-based race conditions. The scenario exactly matches CEH’s description of TOCTOU exploitation, where attackers manipulate file access in the interval between validation and execution.

In CEH v13 Malware Threats, BITS is highlighted as a legitimate Windows service frequently abused by attackers for stealthy command-and-control (C2) communication and data exfiltration. BITS is designed to transfer files in the background using idle bandwidth, primarily for Windows Updates and Microsoft services.

Attackers exploit BITS because its traffic closely resembles legitimate Windows update traffic, which is almost always allowed through firewalls, proxies, and endpoint security controls. This makes malicious traffic blend seamlessly into normal network activity, significantly reducing the likelihood of detection.

Option C correctly captures this behavior. BITS does not rely on IP fragmentation (Option A), DNS encryption (Option B), or exclusive HTTP tunneling (Option D). Instead, it leverages trusted system behavior and signed binaries, allowing malware to “live off the land.”

CEH v13 stresses that abuse of trusted services like BITS is a hallmark of advanced persistent threats (APTs) and fileless malware. Detecting such abuse typically requires behavioral monitoring rather than signature-based detection.

Thus, Option C is correct.

The behavior described most closely matches an insider attack, because the actor is a temporary contractor who has physical proximity and implicit access to internal areas where employees work and handle sensitive information. In CEH guidance, an “insider” is not limited to permanent employees; it includes contractors, vendors, interns, and any trusted or semi-trusted individuals who can enter facilities or access internal environments. The attack combines two common insider-facilitated techniques: shoulder surfing and dumpster diving. Recording employees entering passwords is a form of shoulder surfing, where credentials are harvested by observing or capturing authentication entry through direct viewing or recording devices. Finding sensitive documents in a trash bin indicates dumpster diving, where attackers recover confidential information from improperly disposed materials.

These actions are typically feasible because the attacker is already inside the perimeter and can exploit weak operational security practices, such as lack of clean-desk enforcement, inadequate shredding policies, and insufficient physical monitoring of visitor or contractor activity. CEH materials emphasize that insider threats are particularly dangerous because they bypass many external perimeter controls and can blend into normal workplace behavior.

The other options do not fit. A distribution attack generally refers to compromise introduced through supply chain or third-party distribution channels, not on-site observation and trash retrieval. A passive attack is too generic and does not capture the key element of an authorized or trusted presence enabling the compromise. “Cisco-in attack” is not a standard CEH attack category for this scenario. Therefore, the most accurate classification is an insider attack.

CEH v13 defines the five phases of ethical hacking as a structured methodology that mirrors real-world attack progression:

Reconnaissance – Information gathering

Scanning – Identifying live hosts, ports, and vulnerabilities

Gaining Access – Exploiting vulnerabilities

Maintaining Access – Establishing persistence

Covering Tracks – Removing evidence

Option C matches this exact sequence. CEH v13 emphasizes that understanding this order is critical for both attackers and defenders, as it enables systematic testing and effective mitigation strategies.

All other options misplace phases and contradict the CEH methodology.

Amanda’s primary enumeration focus is a “file transfer” service that allows anonymous login and directory listing. That clearly indicates FTP, which runs on TCP port 21 (control channel). Anonymous FTP misconfiguration is a well-known exposure risk because it can allow unauthenticated users to browse or download files, and sometimes even upload content depending on permissions. Enumerating FTP typically includes validating anonymous access, listing directories, checking readable file contents, identifying writable folders, and verifying whether the server leaks banners, system type, or user/account hints.

The scenario also mentions background UDP traffic related to NetBIOS name lookups, which corresponds to UDP port 137 (NetBIOS Name Service). While NetBIOS is more common in Windows environments, it can still appear on networks with mixed systems or legacy compatibility services. The question asks which ports and services to prioritize given her enumeration activity, which includes FTP access weaknesses and noticing NetBIOS name lookup traffic.

Option B (TCP 21 and UDP 137) matches both:

TCP 21 = FTP control port, directly tied to anonymous login and directory enumeration.

UDP 137 = NetBIOS Name Service, matching the observed name-lookup traffic.

Why the other options don’t fit:

TCP 23 is Telnet (A), not the described file transfer service.

TCP 25 is SMTP (C), unrelated to anonymous file transfer login.

TCP 139 is NetBIOS Session Service (D), more associated with SMB over NetBIOS, not specifically with UDP name lookups, and it omits the FTP port central to her activity.

Therefore, the correct choice is B. TCP 21 and UDP 137.

This scenario represents a Botnet-Based Distributed Denial-of-Service (DDoS) attack, as described in CEH v13 Network Attacks. Compromised internal devices become part of a botnet and are used to launch attacks against external targets.

CEH v13 notes that botnets frequently include IoT devices and employee workstations, making insider-originated DDoS activity a serious concern.