300-215 Exam Dumps : Conducting Forensic Analysis and Incident Response Using Cisco CyberOps Technologies (CBRFIR)

Generic Routing Encapsulation (GRE) is a tunneling protocol used to encapsulate a wide variety of network layer protocols inside point-to-point connections. If packets encapsulated with GRE are bypassing monitoring tools, it's likely due to tunneling—where payloads are hidden within another protocol. Tunneling can obscure malicious content or lateral movement in a network and is a common method used in data exfiltration.

Comprehensive and Detailed Explanation:

The log entries show repeated SSH login attempts for various invalid usernames (e.g., admin, phoenix, rainbow, test, user, etc.) from different source ports. These are clear signs of a brute-force attack—an automated process trying multiple usernames and passwords in hopes of gaining access.

Mitigating such attacks includes:

Implementing account lockout policies (e.g., locking an account after several failed login attempts).

Enabling Multi-Factor Authentication (MFA) to ensure that password guessing alone is insufficient for account access.

Therefore, the correct answer is:

D. Brute-force attack; implement account lockout policies and roll out MFA.

The magic number (also known as a magic byte) is a sequence of bytes used to identify the format of a file. For PDF files, the standard magic number is:

25 50 44 46, which translates to%PDFin ASCII. OptionC(255044462d) begins with25 50 44 46, confirming it's a PDF file signature. This is a key forensic detail when performing file type identification and validation of potentially obfuscated or renamed files.