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

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.

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.

The alert clearly identifies ET SCAN DirBuster Web App Scan in Progress, referencingSID 2008186, which is a Snort signature that specifically detectsDirBusteractivity. DirBuster is a well-known tool used for brute-forcing hidden directories and files on web servers.

The Cisco CyberOps Associate guide and OWASP both identifydirectory brute-forcingas a reconnaissance technique to find unprotected or misconfigured endpoints on web applications, typically prior to launching deeper attacks.

Therefore, the correct interpretation of the alert is:

C. brute-force attack against directories and files on the target webserver.

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.

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 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.

Since the phishing email originates from a known compromised cloud provider (XYZCloud), the correct immediate action for the security analyst is to determine the broader scope of exposure. This involves checking whether other users in the organization received similar emails from the same potentially malicious source. Therefore, querying for emails from theIP address rangesorSMTP domainslinked to XYZCloud is essential for identifying other possible attack vectors.

This step aligns with the containment phase of the incident response lifecycle, as outlined in theCyberOps Technologies (CBRFIR) 300-215 study guide, where threat hunting and log analysis are used to determine the extent of compromise and prevent lateral movement or further exposure. Only after the scope is understood should remediation or reporting actions follow.

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.

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.

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 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 command in the image usesschtasks /createwith theONLOGONschedule andSystemuser context to executetest.exe. This is a well-documented persistence technique, where an attacker ensures that a malicious executable is launched automatically at each system logon. This kind of scheduled task creation aligns with persistence techniques in the MITRE ATT&CK framework (T1053).

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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 Apache access logs in the exhibit show a sequence of HTTP requests and responses indicative of a malicious upload via WordPress:

A POST to:

/wp-admin/admin-ajax.php with parameters that include uploading r57.php (a known PHP web shell).

The uploaded file name appears as r57.php in:? &name=%5B%5D=r57.php&FILES...

There are plugin installation and activation attempts, specifically for:

file-manager plugin:? plugin=file-manager&...

Which is known to be vulnerable and exploited for file uploads.

GET requests to:

/wp-content/57.php and variations such as 57.php?28 — This suggests that r57.php was successfully uploaded and is being accessed.

These logs reveal that:

D. The attacker used the WordPress file manager plugin to upload r57.php — confirmed by plugin activity and file uploads.

B. The attacker uploaded the WordPress file manager trojan — as evidenced by the direct access to /wp-content/57.php (r57 shell variant).

Other options are invalid or speculative:

A is correct in identifying r57 as a web shell, but the logs don't show privilege escalation.

C mentions brute force and SQL injection, which are not indicated here.

E assumes legitimate access — logs suggest exploitation, not standard login.

In phishing incidents, especially with successful lateral movement (land and expand), the most critical factor is usuallyweaknesses in email security systems—such as lack of advanced phishing detection, weak DMARC/DKIM/SPF policies, or insufficient user behavior monitoring. To prevent recurrence, the root cause analysis must focus on what allowed the phishing email to bypass defenses and how initial credentials were compromised.

This aligns with best practices from the Cisco CyberOps v1.2 Guide underEmail Threat Vectors and Security Control Weaknesses.

When analyzing suspicious files in a sandbox environment, a security analyst focuses on identifying and evaluating their behavior in a controlled setting to confirm potential malicious activity:

Inspect processes (B): Observing the processes that the file spawns or injects into during execution helps identify malicious actions or privilege escalation. This is a crucial part of dynamic analysis in the sandbox environment.

Inspect PE header (E): The PE (Portable Executable) header contains metadata about how the file will execute on Windows systems. It reveals details such as the entry point, libraries used, and whether the file is suspiciously crafted or packed, which can be strong indicators of malicious behavior.

The other options (A, C, D) are important in the broader forensic analysis, but within thesandbox dynamic analysis, focusing on process behavior and file execution headers is critical for determining how the file interacts with the system and whether it is indeed malicious.

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.".

The code includes syntax and modules such asimport win32con,import win32api, and uses Python-specific formatting likedef,try/except, andprint, clearly indicating that this is written in Python. It also uses thewmimodule to monitor process creation events—a common technique in Python-based process monitoring scripts on Windows.

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This Python script uses a combination of libraries (urllib,zlib,base64, andssl) to:

Disable SSL certificate verification (ssl.CERT_NONEandcheck_hostname=False).

Construct a custom HTTPS opener with the specified SSL context.

Add a forgedUser-Agentheader to mimic Internet Explorer 11.

Connect to the URLhttps://23.1.4.14:8443 .

Download and execute base64-encoded and zlib-compressed content from that URL using:

exec(zlib.decompress(base64.b64decode(...).read()))

This shows a classic example of:

Downloading payloads from a remote server (23.1.4.14:8443).

Avoiding detection by disabling SSL verification.

Executing the payload dynamically withexec()after decoding and decompressing.

The main goal is clearly to initiate a connection to a remote command-and-control (C2) server on port 8443 and download/execute additional code.

Hence, the correct answer is: A. Initiate a connection to 23.1.4.14 over port 8443.

To prepare a post-incident report, thecauseof the incident (what enabled it) and theeffect(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 withroot cause analysisfollowed by impact assessment to guide future prevention strategies.

When Web Application Firewalls (WAFs) are configured to block specific patterns (like${), attackers may bypass this using URL encoding (e.g.,%24%7B). In such cases, the WAF must decode these patterns before applying matching rules. EnablingURL decodingensures the WAF recognizes encoded payloads and applies protections appropriately. This is a recommended hardening strategy against bypass techniques for command injection and remote code execution.

One of the primary concerns when gathering forensic evidence in public cloud environments is the issue of multitenancy. In a shared cloud infrastructure, multiple tenants (organizations or users) operate on the same physical hardware, using virtualization to logically separate resources. This architecture poses a significant challenge for forensic investigations because:

Forensic investigators must ensure that they do not inadvertently access or expose data belonging to other tenants while collecting evidence.

This can limit access to low-level system data or hardware-level logs that might be essential for a thorough forensic analysis, since providers must enforce strict data isolation policies.

This concern is recognized in industry practices and guidelines, including NIST SP 800-86, which underscores the need to collect data in a forensically sound and legally defensible manner—something made more complex in shared environments.

The Cisco CyberOps Associate guide emphasizes the challenges of evidence handling in cloud environments, stating that "gathering evidence in the cloud must be carefully performed to ensure compliance with legal standards and to respect the boundaries of other tenants' data".

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).

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

TCPsharkis a variant CLI tool used similarly for packet analysis.

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

The Wireshark capture shows a series of HTTP requests and responses:

The client (10.1.21.101) sends a GET request for/Lk9tdZ.

The server (209.141.51.196) responds withHTTP/1.1 302 Found, which is a standard HTTP status code indicating a redirection.

The subsequent GET request from the client is for/files/1.bin, which indicates it followed the redirect.

This behavior confirms that the server is issuing an HTTP 302 redirect from the initial request path/Lk9tdZto/files/1.bin. This is often observed in malware command-and-control behavior or file download staging.

Option A is incorrect: 302 is a status code, not a data size.

Option C is incorrect: port 49723 is a source/destination ephemeral port, not a redirect target.

Option D is incorrect: communication is over HTTP, not HTTPS (which would indicate encryption).

One of the primary challenges of cloud forensics is the inability to physically access the underlying hardware (e.g., the hard drives storing VM or container data). This restricts investigators from performing traditional disk imaging and handling procedures, which are crucial for maintaining evidence integrity. This limitation is widely recognized in cloud forensics frameworks.

Correct answer: C. no physical access to the hard drive.

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.