300-215 Cisco Conducting Forensic Analysis and Incident Response Using Cisco CyberOps Technologies (CBRFIR) Free Practice Exam Questions (2025 Updated)

The first and most important step in forensic analysis is to preserve the integrity of the data. According to best practices outlined in the Cisco CyberOps Associate guide and NIST 800-86, forensic investigators must first produce a forensically sound, bit-by-bit copy of the system’s data (i.e., imaging). This enables analysis to occur without altering the original evidence, which is essential for legal admissibility and maintaining the chain of custody.

According to the Cisco CyberOps Associate guide, the goal of a root cause analysis is to determine how an attacker successfully exploited a system so that similar vulnerabilities can be mitigated in the future. The "method of infection" (e.g., phishing email with malicious attachment, drive-by download, credential compromise, etc.) is the most relevant factor in understanding the initial access vector and subsequent spread of ransomware across the network.

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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.

To prevent macro-based attacks, the Cisco CyberOps study guide emphasizes the importance of limiting execution of unauthorized or unsigned macros. "Requiring that all macros be digitally signed and limiting execution only to those that meet the required trust level is a key mitigation strategy against malicious macros." Additionally, enabling features likeControlled Folder Accesshelps in protecting sensitive directories from unauthorized changes by untrusted applications, including those launched via malicious macros .

These two measures—enforcing signed macro policies and leveraging controlled folder access—directly help in mitigating the risk posed by embedded malicious macros in documents.

The exhibit shows a PowerShell script that modifies registry keys under:

HKCU:\Software\Classes\Folder\shell\open\command

This technique is commonly associated with aUAC (User Account Control) bypass. Specifically:

It creates a new custom shell command path for opening folders.

The key registry property"DelegateExecute"is set, which is a known bypass method. If set without a value, it may cause Windows to run commands with elevated privileges without showing the UAC prompt.

The use ofHKCU(HKEY_CURRENT_USER) rather thanHKLM(HKEY_LOCAL_MACHINE) allows the attacker to bypass permissions since HKCU is writable by the current user. This registry hijack can be leveraged by a malicious actor to execute arbitrary commands with elevated rights.

This is identified in the Cisco CyberOps study material under “UAC bypass techniques,” which describes:

“Attackers often create or modify registry keys like DelegateExecute to hijack the default behavior of applications and elevate privileges”.

Thus, option B is correct: the exhibit demonstrates a UAC bypass using user-accessible registry modification.

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 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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Comprehensive and Detailed Explanation:

The exhibit lists several behaviors under categories such as Remote Access, Stealer/Phishing, Persistence, and Evasive Marks. Notably, under “Persistence” it states:

“Writes data to a remote process”

This behavior is indicative of “process injection,” a technique where malware writes or injects malicious code into the address space of another process. This allows the malware to evade detection and run within the context of a legitimate process.

This matches the MITRE ATT&CK technique T1055 (Process Injection), which is also discussed in the Cisco CyberOps Associate guide under evasion and persistence tactics used by malware.

While modified registry and data compression are possible signs of malware, they are not explicitly referenced in the exhibit. The definitive indicator shown is related to process injection.

Therefore, the correct answer is: C. process injection.

The correct next step in analyzing the malicious nature of the email is toevaluate the artifactsinCisco Secure Malware Analytics(formerly Threat Grid). This tool provides a comprehensive sandbox environment where behavioral indicators like file execution, registry access, and domain connections are logged and scored.

The exhibit shows:

Remote PowerShell execution

Executable download from a flagged domain

SHA256 hash linked to malware

All these artifacts, as labeled in the Secure Malware Analytics output, arekey indicators of compromise, and analyzing them further can confirm whether the email was part of a malicious campaign.

Thus, the best action is:

A. Evaluate the artifacts in Cisco Secure Malware Analytics.

Input validation (A) is a critical countermeasure to defend against command injection and related vulnerabilities, as discussed in the Cisco guide. Proper validation ensures that malicious commands or payloads are not accepted or executed by the web application.

File integrity monitoring (E) helps detect unauthorized changes such as log deletion or binary modification, making it a crucial tool in recognizing and investigating tampering attempts.Blocking port 443 (B) would disable HTTPS and is not a practical solution. Antivirus (C) does not prevent form-based application attacks, and merely updating the application (D) may not be sufficient without addressing the underlying input validation flaw.

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The exhibit shows multipleARP reply packetswith the same IP addresses (192.168.51.105and192.168.51.201) being mapped todifferent MAC addresses, which triggers the message: "duplicate use of [IP] detected". This is a strong indicator of anARP spoofing(or poisoning) attack.

ARP spoofing occurs when a malicious actor sends falsified ARP messages to associate their MAC address with the IP address of another host. This misleads other devices on the network and allows interception or redirection of traffic.

The Cisco CyberOps Associate guide specifically recommendsconfiguring port securityon switches as a method tomitigate ARP spoofing, by limiting the number of MAC addresses allowed per port or statically assigning legitimate MAC addresses to switch ports.

The XML (STIX/CybOX format) details anemail-based threatindicator. Specifically:

Theemail addresscontains “@state.gov” (not exact match, so blocking all @state.gov would be overbroad).

Theattachment is a PDFfile with a specifiedMD5 hash: cf2b3ad32a8a4cfb05e9dfc45875bd70.

Theattachment sizeis 87022 bytes.

From a threat mitigation perspective:

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

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

Incorrect options:

Boverreaches by blocking an entire domain without confirming threat context.

Cwould stop all PDFs, which is impractical.

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

Using adifferent IP addressto disguise the origin of an attack is the definition ofIP spoofing.

“Spoofing involves falsifying data, such as IP or MAC addresses, to hide the source of malicious activity.” — Cisco CyberOps guide