Free Cisco 300-215 Practice Exam with Questions & Answers | Set: 3

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.

In the provided Wireshark capture, we see multiple TCP SYN packets being sent from different source IP addresses to the same destination IP address (192.168.1.159:80) within a short time window. These SYN packets do not show a corresponding SYN-ACK or ACK response, indicating that these TCP connection requests are not being completed.

This pattern is indicative of a SYN flood attack, a type of Denial of Service (DoS) attack. In this attack, a malicious actor floods the target system with a high volume of TCP SYN requests, leaving the target's TCP connection queue (backlog) filled with half-open connections. This can exhaust system resources, causing legitimate connection requests to be denied or delayed.

The countermeasure for this scenario, as highlighted in the CyberOps Technologies (CBRFIR) 300-215 study guide under Network-Based Attacks and TCP SYN Flood Attacks, involves:

Increasing the backlog queue: This allows the server to hold more half-open connections.

Recycling the oldest half-open connections: This ensures that legitimate connections have a chance to be established if the backlog fills up.

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/messages provide critical system error reporting including shutdowns, memory errors, and service failures".

A disassembler is a forensic and reverse engineering tool that translates machine-level code (binary) back into human-readable assembly language. This is used during static malware analysis to understand how the malware is constructed and what it is designed to do without actually executing the code.

According to the CyberOps Technologies (CBRFIR) 300-215 study guide, “Disassembler tools are used to assist with reverse malware engineering by allowing a security professional to examine the binary and understand the functionality of the malware code”.

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Process Explorer is an advanced Windows-based utility that shows real-time data about running processes, CPU usage, services, DLLs, and handles. It is specifically designed for this kind of investigation and is part of the Sysinternals Suite.

The described scenario includes both internal alerts (unusual network traffic, failed logins, suspicious file access) and external intelligence indicating active ransomware campaigns in the same industry. This constitutes a strong combination of precursors and indicators, as defined in the NIST SP 800-61 incident handling model and reinforced in the Cisco CyberOps Associate curriculum.

According to the Cisco guide:

“Once an incident has occurred, the IR team needs to contain it quickly before it affects other systems and networks within the organization.”

“The containment phase is crucial in stopping the threat from spreading and compromising more systems”.

Given these indicators and the high-value nature of the data involved, it is essential to proactively isolate suspected systems and activate the incident response plan to prevent damage from potential ransomware.

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YARA rules are primarily used for malware classification and detection based on binary pattern matching within files. They describe sequences of bytes, strings, and other file characteristics found in malicious binaries.

The Cisco CyberOps Associate guide explains: "YARA rules operate by inspecting binary data using conditions and string matches to identify specific patterns that indicate known malware samples.".

The Cisco study material recommends integrating automation for log/event collection and contextual analysis to reduce detection delays and ensure rapid identification of anomalies. It also emphasizes the need for pre-defined roles and documented steps in an Incident Handling Playbook, following NIST SP 800-61 Rev.2 standards, to improve consistency and readiness during incidents.

To prepare a post-incident report, the cause of the incident (what enabled it) and the effect (what damage was done) are the primary components analyzed first. This allows teams to understand vulnerabilities exploited and the consequences, forming the basis for corrective action.

The Cisco CyberOps guide recommends beginning with root cause analysis followed by impact assessment to guide future prevention strategies.

YARA rules are pattern-matching rules used to identify malware based on specific strings, conditions, and binary patterns. They are most effective in memory or file scans where analysts search for known indicators or unique signatures via string matching.

Correct answer: C. string matching.