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

Covert channel communication is one of the most sophisticated evasion techniques described in CEH v13 Evasion Techniques. By embedding malicious data within unused or rarely inspected protocol fields (such as IP headers), attackers can bypass firewalls, IDS, and IPS systems entirely.

Unlike polymorphic malware (Option C), which can still be detected using behavior analysis, covert channels blend seamlessly into legitimate traffic. Packet fragmentation (Option D) is well-known and often mitigated. Honeypot spoofing (Option B) is rare and defensive in nature.

CEH v13 emphasizes that covert channels are difficult because:

They do not violate protocol specifications

They evade signature-based and stateful inspection

They appear as normal traffic

Detecting covert channels often requires deep protocol analysis and statistical traffic inspection, making them extremely challenging to mitigate.

Thus, Option A is the correct answer.

This question relates to Malware Analysis, specifically PDF-based malware, as covered in the CEH v13 Malware Threats module. The presence of /JavaScript and /OpenAction keywords identified by pdfid strongly indicates potentially malicious behavior triggered when the PDF is opened.

CEH v13 recommends static analysis of PDF stream objects as the next step to understand embedded malicious logic. Tools such as PDFStreamDumper allow analysts to extract, decompress, and inspect object streams within a PDF file, revealing obfuscated JavaScript code or exploit payloads.

The /OpenAction keyword indicates that the embedded JavaScript executes automatically when the document is opened, a common technique used in PDF-based attacks to exploit reader vulnerabilities or download secondary payloads.

Other options are insufficient:

VirusTotal provides detection results but not behavioral insight.

PE Explorer is irrelevant because PDFs are not Portable Executable files.

Hashing only helps identify known malware, not analyze behavior.

CEH v13 emphasizes manual inspection of embedded scripts to determine intent, making PDFStreamDumper the correct next step.

Comprehensive and Detailed Explanation From CEH v13 Guide:

Grey-box testing is a hybrid method where the tester has partial knowledge of the internal workings of the system, allowing for a more focused and efficient assessment of security vulnerabilities compared to black-box (no knowledge) and white-box (full knowledge). This approach simulates an insider threat or a user with limited access rights.

CEH v13 Reference:

Module 15: Hacking Web Applications – Types of Penetration Testing

“Gray-box testing assumes partial knowledge of internal structures, combining elements of both black-box and white-box testing.”

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This scenario describes Living-off-the-Land (LotL) malware techniques, where attackers modify or abuse legitimate system binaries and services to evade detection. CEH v13 identifies this as a highly stealthy persistence mechanism commonly used in advanced persistent threats (APTs).

The most effective countermeasure is file integrity monitoring (FIM), specifically by tracking cryptographic hashes of critical system executables. CEH v13 emphasizes that monitoring file hashes enables early detection of unauthorized modifications to binaries such as PowerShell, cmd.exe, or Windows services.

Backups (Option A) aid recovery but do not prevent or detect compromise. Antivirus updates (Option C) often fail against modified legitimate tools. Firewall hardening (Option D) reduces attack surface but does not detect tampering of trusted binaries.

CEH v13 explicitly recommends hash-based integrity verification as a core defense against stealthy persistence mechanisms. Therefore, option B is correct.

An HTTP Flood attack is an Application Layer (Layer 7) DDoS attack, as defined in CEH v13. In this attack, the adversary sends a massive number of seemingly legitimate HTTP GET or POST requests to exhaust server resources such as CPU, memory, and application threads.

CEH v13 emphasizes that HTTP floods are difficult to detect because they mimic normal user behavior and often bypass traditional network-layer defenses.

Other attacks operate at lower layers:

ICMP, UDP, and SYN floods target network and transport layers.

Comprehensive and Detailed Explanation:

In Windows SID structure:

RID 500 = Default Administrator

RID 501 = Guest Account

Therefore, “-501” at the end indicates Matthew is operating as the Guest user, which has very limited privileges. To gain full administrative control, he must escalate his privileges.

From CEH v13 Courseware:

Module 6: System Hacking → Privilege Escalation Techniques

We have various articles already in our documentation for setting up SNMPv2 trap handling in Opsview, but SNMPv3 traps are a whole new ballgame. They can be quite confusing and complicated to set up the first time you go through the process, but when you understand what is going on, everything should make more sense.

SNMP has gone through several revisions to improve performance and security (version 1, 2c and 3). By default, it is a UDP port based protocol where communication is based on a ‘fire and forget’ methodology in which network packets are sent to another device, but there is no check for receipt of that packet (versus TCP port when a network packet must be acknowledged by the other end of the communication link). 

There are two modes of operation with SNMP – get requests (or polling) where one device requests information from an SNMP enabled device on a regular basis (normally using UDP port 161), and traps where the SNMP enabled device sends a message to another device when an event occurs (normally using UDP port 162). The latter includes instances such as someone logging on, the device powering up or down, or a wide variety of other problems that would need this type of investigation.

This blog covers SNMPv3 traps, as polling and version 2c traps are covered elsewhere in our documentation.

SNMP traps

Since SNMP is primarily a UDP port based system, traps may be ‘lost’ when sending between devices; the sending device does not wait to see if the receiver got the trap. This means if the configuration on the sending device is wrong (using the wrong receiver IP address or port) or the receiver isn’t listening for traps or rejecting them out of hand due to misconfiguration, the sender will never know.

The SNMP v2c specification introduced the idea of splitting traps into two types; the original ‘hope it gets there’ trap and the newer ‘INFORM’ traps. Upon receipt of an INFORM, the receiver must send an acknowledgement back. If the sender doesn’t get the acknowledgement back, then it knows there is an existing problem and can log it for sysadmins to find when they interrogate the device.

The Certified Ethical Hacker (CEH) Cryptography module explains that one of the primary challenges in encryption is secure key distribution. Asymmetric encryption, also known as public-key cryptography, was specifically designed to address this issue.

In asymmetric encryption, each entity possesses a public key and a private key. The public key can be shared openly, allowing anyone to encrypt data securely, while only the corresponding private key can decrypt it. CEH documentation highlights that this model eliminates the need to transmit secret keys over insecure channels.

Option D is correct because asymmetric encryption enables secure key exchange without prior trust.

Option B (symmetric encryption) requires a shared secret key and suffers from key distribution challenges.

Option A refers to data-at-rest protection, not key exchange.

Option C provides integrity verification, not encryption.

CEH emphasizes that asymmetric encryption underpins secure protocols such as TLS and digital certificates.