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

TCPdump is a CLI-based packet capture tool that is widely used for real-time traffic inspection and analysis on Unix/Linux systems.

TCPshark is a variant CLI tool used similarly for packet analysis.

Although Wireshark is a powerful network protocol analyzer, it requires a GUI. Therefore, it is not suitable for environments without a graphical interface.

According to the Cisco Certified CyberOps Associate guide (Chapter 5 - Identifying Attack Methods), attachments in emails—especially with file extensions like .xlsm—are high-risk indicators when analyzing suspicious or phishing emails. Malicious actors often use macro-enabled Excel files (.xlsm) as a payload delivery mechanism for malware or other exploits. These attachments are typically disguised as legitimate content such as refunds or invoices to trick the recipient into opening them.

The presence of “Card_Refund_18_6913.xlsm” is a strong Indicator of Compromise (IoC), as .xlsm files can contain VBA macros capable of executing malicious code. This matches exactly with examples provided in the study material discussing how macro-based payloads are delivered and recognized.

Hence, option C is the most direct indicator of attack in this email.

The XML (STIX/CybOX format) details an email-based threat indicator. Specifically:

The email address contains “@state.gov” (not exact match, so blocking all @state.gov would be overbroad).

The attachment is a PDF file with a specified MD5 hash: cf2b3ad32a8a4cfb05e9dfc45875bd70.

The attachment size is 87022 bytes.

From a threat mitigation perspective:

A is correct: Updating AV to block or flag files matching the malicious hash is a standard response.

D is correct: The email address context and hash together provide a precise rule for blocking—this prevents false positives.

Incorrect options:

B overreaches by blocking an entire domain without confirming threat context.

C would stop all PDFs, which is impractical.

E is incorrect; there is no indication that the hash appears in the subject line.

A “malicious insider” is someone within the organization who has authorized access but intentionally misuses that access to extract or exfiltrate data. In this case:

The HR user has legitimate access but deviates from their normal behavior pattern (accessing legal data daily instead of monthly).

The presence of large data dumps and the alert from a threat intelligence platform suggest intentional misuse rather than accidental behavior.

According to the Cisco CyberOps Associate guide, insider threats are identified by behavioral anomalies, especially involving sensitive data access patterns inconsistent with role-based access and historical usage profiles.

The string in the exhibit is a classic example of Base64 encoding. Base64 is used to encode binary data into ASCII characters, making it suitable for transmitting data over media that are designed to deal with textual data. It typically ends with one or two equal signs = (padding), which this string does. This format is commonly seen in obfuscated payloads or malware communications in the wild.

The root cause analysis report’s main goal is to identify what allowed the ransomware to successfully infect systems. The Cisco CyberOps Associate guide emphasizes the importance of uncovering and mitigating the actual vulnerabilities that were exploited during an incident. These could include outdated software, unpatched systems, or poor access control. While understanding the encryption technique or C2 server is helpful for threat intelligence, it does not address the root cause.

The guide states:

"Effective IR helps professionals to leverage the information collected from a security incident to better understand the intrusion and its functionality… this data helps the security team to be better prepared and equipped to handle future incidents".

Identifying the exploited vulnerabilities enables future prevention strategies such as patch management, configuration hardening, and reducing attack surfaces.

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