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

Cisco Secure Endpoint (formerly AMP for Endpoints) offers features like:

File trajectory: to track file behavior and spread across endpoints.

Orbital Advanced Search: for querying endpoint data to detect threats in real time.

Cisco Secure Malware Analytics (formerly Threat Grid) enables deep file behavior analysis, including TCP/IP stream analysis and behavioral indicators such as file system activity, process injection, registry changes, and command and control communication. These are essential in understanding what the suspicious file does post-execution, especially given the described behavior of creating a fake folder and outbound connection attempts.

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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.

Comprehensive and Detailed Explanation:

Endpoint Detection and Response (EDR) tools provide behavioral analytics and continuous monitoring to detect malware such as backdoors, which is especially critical on endpoints like macOS devices. These tools are essential to detect post-compromise activities and contain threats before they spread.

Secure Email Gateway (e.g., Cisco ESA) plays a key role in blocking phishing emails—the initial vector in this attack. It uses filters and reputation analysis to prevent malicious links or attachments from reaching end users.

Incorrect Options:

C. DLP focuses on preventing data exfiltration, not phishing prevention or backdoor detection.

D. IPS is effective for known signature-based threats but less effective against phishing links and endpoint-level backdoors.

E. WAF protects web servers, not end-user devices from phishing or backdoor infections.

Therefore, the correct answers are: A and B.

The correct registry path to investigate user profiles and login details is:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\ProfileList

This location stores information about each user profile on the machine, including login activity and the LastWrite time for forensic tracking.

Antiforensic techniques are methods attackers use to cover their tracks. According to the Cisco CyberOps curriculum, “obfuscation” refers to techniques such as encoding, encrypting, or otherwise disguising commands, payloads, or scripts to avoid detection and analysis. This is a standard antiforensic tactic used to prevent attribution and hinder forensic investigation.

Options like privilege escalation and authentication are part of attack vectors or access control and not antiforensic methods.

TCPdump is a command-line packet analyzer used to capture and inspect network packets. As described in the study guide, "tcpdump is a command-line interface tool that is used to capture packets on a network. It is a very powerful and popular network protocol analyzer". The tool allows cybersecurity professionals to analyze headers and payloads of network traffic, making it valuable in forensic investigations and network diagnostics.

The observed process tree (AcroRd32.exe→cmd.exe→powershell.exe) strongly suggestsmalicious behavior, particularly inPDF-based malware attacksleveraging embedded scripts or exploits.

Ais correct: Submitting the suspicious PDF toCisco Threat Gridallows sandbox analysis to detect hidden malicious behaviors.

Dis correct: The suspicious activity warrantsquarantining the hostto contain potential spread or further compromise.

The best immediate step during a DDoS attack against an Apache web server is to inspect theaccess logs, which will show which IP addresses are making requests, their frequency, and potential patterns of abuse. As covered in the Cisco CyberOps material, "Apache logs can reveal the IPs responsible for flooding the service with requests". The commandsudo tail -100 /var/log/apache2/access.logallows quick review of recent activity.

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.

From the Wireshark capture:

A (iraniansk.com): This domain isnot a known legitimate resourceand is hosting a suspicious file named “Fy.exe,” strongly indicative of amalware distribution domain.

D (Fy.exe): TheContent-Disposition: attachment; filename="Fy.exe"header explicitly signals abinary executabledownload, a key indicator in Emotet campaigns.

WhileContent-Type: application/octet-stream(E) is typical of binary data transfers, it isnot uniqueto malware and cannot by itself serve as a strong IoC. Thenginx server (B)andcookie/hash string (C)similarly do not uniquely indicate compromise.

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

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.

The use of repetitive patterns in images is a known indicator of steganography, which is an anti-forensics technique used to hide malicious code or files inside seemingly benign content such as image or audio files. The repetitive patterns suggest that the image may contain embedded hidden data. This technique is particularly difficult to detect through conventional scanning or antivirus software.

According to theCyberOps Technologies (CBRFIR) 300-215 study guide, steganography is defined as “concealing malicious content or instructions within ordinary files such as .jpg, .png, or audio files, allowing the content to bypass security filters and reach the target system without detection”.

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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 rulesare primarily used for malware classification and detection based onbinary pattern matchingwithin 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.".

When suspicious activity is detected on a workstation, immediate steps need to be taken to preserve evidence and prevent further compromise:

Disconnecting the system from the network (C)is crucial to stop potential exfiltration of data or ongoing communications with a command-and-control server. This isolation prevents further spread or damage while preserving the state of the compromised system for further investigation.

Taking an image of the workstation (E)is part of the forensics acquisition process. It involves creating a bit-by-bit copy of the system’s disk, which preserves all evidence in its current state. This allows for thorough forensic analysis without affecting the original evidence.

These steps align with the best practices outlined in the incident response and forensics processes (as described in theCyberOps Technologies (CBRFIR) 300-215 study guide). Specifically, in theIdentification and Containmentphases of the incident response cycle, it’s emphasized that isolating the system and preserving evidence through imaging are critical to ensuring both containment of the threat and successful forensic investigation.

The STIX intelligence feed in the exhibit identifies specific malicious domains, such as:

fightcovid19.shop

nocovid19.shop

stopcovid19.shop

These are categorized as “Malicious FQDN Indicator.” The recommended cybersecurity actions when such threat intelligence is received are:

D. Block network access to identified domains: This directly prevents users or systems from communicating with known malicious infrastructure and is a critical first step in threat mitigation.

B. Add a SIEM rule to alert on connections to identified domains: This ensures that any attempted communication with these domains is flagged for immediate review and action, enabling real-time threat detection and incident response.

Blocking all .shop domains (Option A or C) would be overbroad and potentially disruptive, as many legitimate websites also use that TLD. Option E (routing to block hole) could be valid as a DNS strategy, but B and D represent the most actionable and precise responses per standard incident response practices.

This scenario describes asubstitution cipher, where data is made unreadable or less recognizable without altering its functionality. According to the Cisco CyberOps Associate guide, obfuscation includes techniques such as shifting, encoding, and symbol manipulation to mask the true nature of data or code:

"A very well-known cipher, the Caesar cipher... shifts the letter of the alphabet by a fixed number... This technique is a form of data obfuscation used to bypass detection mechanisms.".

According to the event log, a suspicious service was installed (DIAOHHNMPMMRgji) with a service file pointing to a remote share (\\127.0.0.1\admin$\EqnBqKWm.exe). This type of activity strongly suggests:

A. Unauthorized system modification: Installation of a service without proper authorization, especially with a random or obfuscated name, directly fits the description of system modification. The use of admin$ (administrative share) further implies this wasn't part of standard operations.

E. Malware outbreak: The use of a service that points to an executable with a seemingly random name and the demand start configuration indicate a potential backdoor or remote-controlled malware. As stated in the Cisco CyberOps Associate guide, event ID 7045 with unusual service names or file paths is a strongIndicator of Compromise (IoC)for malware or persistence mechanisms.

Options like privilege escalation or DoS are not directly evidenced in the event log shown. There's no indication that the LocalSystem account was elevated beyond its default, nor that system resources were overwhelmed (as would be typical in DoS).

The eradication phase in incident response involveseliminating the root cause of the incidentand strengthening defenses to prevent reoccurrence. In this case:

Intrusion Prevention System (D): Adding new rules to the IPS to detect and block malicious activity on TCP/135 is a direct eradication step to remove the threat’s entry point and prevent future attacks.

Centralized User Management (C): Hardening user accounts, removing unnecessary permissions, and applying tighter authentication/authorization measures helps eliminate the possibility that threat actors could exploit weak or mismanaged accounts to continue accessing the system.

Althoughanti-malware software (A)andenterprise block listing (E)are valuable, themost direct eradication stepshere specifically involve managing network access (via IPS) and strengthening user controls (via centralized user management), especially when TCP/135 (MSRPC endpoint mapper) can be used to enumerate services and potentially access vulnerable endpoints remotely.

This aligns with best practices outlined in incident response frameworks (such as the NIST SP 800-61 and referenced resources), which emphasizeclosing the exploited entry points(in this case, TCP/135) andremoving any lingering access pointsthrough user management and network control enhancements.

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.

Fileless malwareoperates in memory and often leverages legitimate tools such asPowerShellto avoid traditional file-based detection. Since these threats don't leave typical file traces, analysts must rely onPowerShell event logsto trace suspicious or unauthorized script execution.

The Cisco CyberOps Associate guide explicitly states:

“PowerShell logs provide insight into script block execution and can reveal indicators of fileless attacks that reside in memory.”

Hence,PowerShell event logsare the most effective forensic source for detecting fileless malware activity on Windows systems.

In VMware ESXi systems, the vmksummary.log file is responsible for capturing general system events, including uptime, reboot statistics, and key service-related issues. It serves as a valuable source for troubleshooting persistent or unexplained system behaviors.

The Cisco CyberOps study guide references log file paths used in system diagnostics and incident response, and for authentication-related issues on ESXi where standard logs don't yield insights, vmksummary.log is the recommended next source for identifying systemic service faults or anomalies.

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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.

The string shown is long, alphanumeric, and includes both uppercase and lowercase letters with numbers—characteristics of Base64 encoding. This format is widely used to obfuscate payloads in malicious scripts, particularly in phishing or malware campaigns. Base64 encoding is also supported by Python and other platforms for data transformation.

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The metadata in the exhibit reveals a strong indicator that this .LNK file (shortcut) is malicious:

The shortcut file is named "ds7002.pdf" but actually points to the execution of PowerShell:→ Full path: C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe

Arguments include:→ -noni -ep bypass $z = '...'; indicating an attempt to run a PowerShell script with execution policy bypassed (a known tactic for fileless malware delivery).

The file is masked as a PDF (common social engineering technique), and PowerShell execution via .LNK is a signature technique used by many malware families to initiate second-stage payloads or scripts.

Given this, the correct and safest course of action is to:

→ Open the .LNK file in a sandbox environment (D).

This enables safe behavioral analysis to observe what actions it attempts upon execution without endangering live systems.

Other options are inappropriate:

A (ignoring the threat due to extension) is dangerous — .LNKs can trigger code.

B (upload to virus engine) is only helpful for known malware and lacks behavioral context.

C (quarantine) is preventive but not investigative — sandboxing provides visibility.

The exhibit shows a series of process executions that form a suspicious chain involving scripting engines and obfuscated commands:

One critical indicator iscmd.exe executing PowerShell with obfuscated (Base64-encoded) arguments. The use of Base64 is a known method used by attackers to mask malicious commands. This aligns with attack techniques defined under MITRE ATT&CK T1059 (Command and Scripting Interpreter) and T1086 (PowerShell abuse). Therefore, option D is valid.

Another important IOC isWScript.exe acting as a parent of cmd.exe, which is abnormal in typical business environments. This indicates potential misuse of Windows Script Host (WSH) to launch commands, often seen in phishing or malware dropper scenarios. Thus, option E is also valid.

Options A and B by themselves are not definitive IOCs—PowerShell and cmd.exe are legitimate administrative tools and frequently used in Windows environments.

Option C is not supported by the exhibit—the reverse (powershell.exe initiated by WScript.exe) is what's seen, not the other way around.

These patterns align with theCyberOps Technologies (CBRFIR) 300-215 study guide, which specifies that chaining of interpreters (e.g., WScript → cmd → PowerShell) with encoded commands is a key indicator of compromise during forensic analysis.