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

Comprehensive and Detailed Explanation:

The log entry contains the following key elements:

The timestamp:(04/Jan/2022:20:18:06 +0000)

HTTP method and URI:"GET /%60%60%60%60%60%60/ HTTP/2.0"

HTTP status code:404

User-Agent:Mozilla/5.0 ... Firefox/95.0

The status code404indicates that the requested resource was not found on the server. This is a standard HTTP response that signifies the server could not locate the requested URI (in this case, likely due to a malformed or invalid path/\`````/, where%60is the URL-encoded form of the backtick character "").

There is no clear evidence of SQL injection, WAF detection, or redirection in this log. The use of encoded backticks may suggest probing behavior, but the log does not show a definitive attack signature.

Therefore, the correct interpretation is:

Answer: D. The requested page was not found.

Once an incident has occurred, the appropriate course of action is to engage the organization's Incident Response (IR) plan. This is a structured approach to contain, analyze, and eradicate threats before they spread across the network.

The Cisco CyberOps Associate study guide emphasizes:

“Incident response and handling are essential within an organization… The main objective of implementing an incident handling process is to reduce the impact of a cyber-attack, ensure the damages caused are assessed, and implement recovery procedures”.

In particular, the containment phase of IR is focused on isolating the threat and preventing lateral movement or further compromise.

Options such as "root cause" or "attack surface" are relevant at later stages of analysis and mitigation, not immediate containment. Therefore, the correct answer is C.

The goal of the given Python code is to parse an Apache access log and extract IP addresses using regular expressions (regex). In this context, the most appropriate regex pattern to extract IPv4 addresses from log data is:

r'\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}'

This pattern matches typical IPv4 addresses, where each octet consists of 1 to 3 digits separated by periods. For example, it matches addresses like192.168.1.1or10.0.0.123. The pattern uses:

\d{1,3}to capture between 1 and 3 digits,

\.to match the dot (escaped since.is a special character in regex),

repeated 4 times with proper separation to form the full IPv4 structure.

Options A, B, and C either include incorrect syntax, improper escape sequences, or do not represent a valid IP address pattern.

This type of log analysis and pattern extraction is described in the Cisco CyberOps Associate curriculum under basic scripting and automation techniques used in log and artifact analysis.

The event log shown in the exhibit isEvent ID 104, which in Windows indicates"The audit log was cleared."This is a significant indicator oflog tampering, a common post-exploitation technique used by attackers to hide their tracks after exfiltrating data or performing unauthorized actions.

The Cisco CyberOps Associate guide mentions:

"Log deletion events, especially Event ID 104, should be treated as potential evidence of malicious activity attempting to cover tracks".

Combined with large data dumps to network shares, this indicates not only unauthorized activity but also deliberate efforts to erase forensic evidence—characteristic oflog tampering.

According to the MITRE ATT&CK matrix, when encrypted traffic is tunneled through a legitimate protocol such as HTTP (port 80) to a non-malicious domain, this aligns with the tactic “Exfiltration Over Asymmetric Encrypted Non-C2 Protocol” (T1048.002). The attacker is trying to hide exfiltration in otherwise benign traffic.

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.

The most relevant log for system-level events such as memory exhaustion and shutdown is/var/log/messages.log, which contains kernel and service-level logs including OOM (Out-Of-Memory) events.

As detailed in Linux investigations:

"Logs located in/var/log/messagesprovide critical system error reporting including shutdowns, memory errors, and service failures".

The code in the exhibit is written in Python. Here’s how we can confirm:

The function definition uses Python syntax: def function_name(args):

It uses the b64encode and decode functions — typical of Python’s base64 module.

Data structures such as dictionaries are used with curly braces (e.g., form_data = {entry1: enc1, ...}).

The conditional syntax uses “if r.status_code == 200:” which is Pythonic.

The request object “r = post(...)” and use of headers show standard use of the Python requests library.

This type of script is typical in exfiltration scenarios where encoded information is sent via a web form (in this case Google Forms), bypassing detection systems.