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

The correct answer is D. Ciphertext-Only Attack.

A ciphertext-only attack occurs when the attacker has access only to encrypted data and does not have the corresponding plaintext or the ability to choose plaintext/ciphertext pairs. That exactly matches the scenario: the attacker has encrypted database backups but no keys and no known plaintext records.

CEH-aligned cryptography material defines a ciphertext-only attack as a cryptographic attack where the cryptanalyst has access to ciphertext but does not have access to the corresponding plaintext. The attacker attempts to recover plaintext or infer the key from encrypted output alone .

Option A. Chosen-Ciphertext Attack is incorrect because the attacker would need to choose ciphertexts and observe their decrypted plaintexts.

Option B. Known-Plaintext Attack is incorrect because the attacker would need both plaintext and corresponding ciphertext.

Option C. Chosen-Plaintext Attack is incorrect because the attacker would need the ability to choose plaintexts and obtain their ciphertexts.

Option D. Ciphertext-Only Attack is correct because the attacker only possesses encrypted data.

Therefore, the best answer is D. Ciphertext-Only Attack.

In CEH v13 Cloud Computing, APIs are identified as the primary control plane for managing cloud resources. A vulnerability in a cloud API can allow attackers to bypass authentication, escalate privileges, and manipulate resources.

Unauthorized access may lead to:

Data exposure

Resource abuse

Account takeover

Lateral movement within the cloud environment

Physical security (Option A) and encryption at rest (Option D) are unrelated to API flaws. DDoS attacks (Option C) are possible but not the primary risk of API vulnerabilities.

Thus, Option B is correct.

Cloud-based DDoS mitigation services provide upstream traffic scrubbing, detecting and filtering high-volume attacks such as DNS amplification and HTTP floods before the traffic reaches the victim’s network. These services use distributed infrastructures capable of handling multi-vector attacks that surpass the capacity of traditional on-premises firewalls and IDS. Traffic scrubbing centers distinguish legitimate traffic from malicious traffic, allowing normal operations to continue without service disruption.

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.

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 evidence points to a User Account Control bypass. In CEH coverage of Windows privilege escalation, UAC is a protection mechanism intended to prevent silent elevation of privileges, typically prompting the user when an action requires administrative rights. However, certain Windows binaries are “auto-elevate” (often trusted, signed Microsoft executables) and can run with elevated privileges under specific conditions without showing a UAC prompt. Attackers abuse this behavior by manipulating user-writable registry locations—commonly under the current user hive—to influence how these trusted binaries launch other components.

The scenario describes exactly that pattern: a non-elevated process starts an auto-elevate executable such as fodhelper.exe, eventvwr.exe, or sdclt.exe, and the system executes unauthorized code with no prompt. The key forensic clue is “manipulation of shell-related keys under the current user hive,” which is a hallmark of UAC bypass techniques that hijack file association or shell open commands so the trusted binary invokes an attacker-controlled payload instead of the intended system action. Because the modification occurs in HKCU, it can often be performed without administrator privileges, making it attractive for stealthy elevation.

The other options do not match as well. Kernel exploitation involves abusing OS kernel vulnerabilities and would not hinge on shell registry hijacks. Scheduled tasks typically leave task artifacts and are a persistence/execution method rather than this specific auto-elevate redirection behavior. DLL hijacking focuses on search-order abuse for loading malicious DLLs, not shell key redirection tied to UAC auto-elevation.

The most likely missing BYOD guideline is reviewing application permissions before installation. In CEH mobile security guidance, a major risk in BYOD environments is the introduction of untrusted or malicious applications that abuse the mobile permission model to access corporate data, intercept authentication tokens, read storage, capture keystrokes via accessibility services, or communicate externally. When users install apps without scrutinizing requested permissions, they may unknowingly grant excessive privileges that enable data theft or access-control bypass, especially if the app leverages OS weaknesses or misconfigurations.

The scenario states Javier “installs a malicious app that bypasses access controls” and gains access to sensitive financial data because devices “lack a specific security measure to restrict app access.” This maps directly to a policy gap around controlling and validating apps and their permission requests. CEH emphasizes that organizations should reduce attack surface by limiting app privileges, avoiding sideloading from untrusted sources, and enforcing least privilege through user awareness and enterprise controls such as MDM application allowlisting and permission governance. Reviewing permissions is the user-facing guideline that prevents employees from granting dangerous access (for example, SMS, storage, contacts, accessibility, device admin, or VPN configuration permissions) that can enable credential theft or unauthorized data access.

Option B adds an extra layer for local access but does not stop a malicious app with granted permissions from accessing corporate data. Option C helps if a device is physically stolen, but it does not prevent malicious apps already running under the user context. Option D protects data at rest, yet a malicious app can still exfiltrate data once it is decrypted and accessed by the user session. Therefore, permission review is the most directly relevant missing BYOD guideline.

Whaling is the correct answer because the scenario describes a highly targeted phishing attempt aimed at a “big fish”—a senior executive (the CEO). In CEH terminology, whaling is a specialized form of phishing that focuses on high-profile, high-authority individuals (e.g., CEOs, CFOs, directors) to maximize impact. These targets often have access to sensitive data, financial approvals, privileged systems, and strategic communications, making their credentials significantly more valuable than those of typical employees.

The attacker (Clara) uses classic social engineering drivers emphasized in CEH training: authority (impersonating the legal department), urgency/fear (a “pending lawsuit”), and trust in internal processes (a link to a supposed internal portal). This combination is designed to short-circuit normal verification behavior and prompt quick compliance. The inclusion of a credential-harvesting link aligns with common phishing goals: capturing usernames/passwords, enabling account takeover, and potentially facilitating broader compromise (e.g., email access for business email compromise, lateral movement, or privileged escalation).

Why the other options are less accurate: Spear phishing is also targeted, but it is a broader category aimed at specific individuals or groups at any level. The defining clue here is the executive-level target, which elevates it to whaling. Clone phishing involves copying a legitimate email previously received and swapping a malicious link or attachment—this detail is not present. Consent phishing typically abuses legitimate OAuth/app consent flows rather than a fake portal requesting credentials.