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

The safest and most effective approach is to isolate the files and subject them to heuristic and behavioral analysis. This can reveal obfuscated malware or unauthorized data storage techniques, even if signature-based antivirus fails to flag them.

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 error logs indicate multiplePKCS12andASN.1 decodingerrors, such as:

PKCS12 routines:PKCS12_parse:mac verify failure

rsa routines:old_rsa_priv_decode:RSA lib

PKCS12 routines:PKCS12_key_gen_uni:malloc

These specific errors most commonly occur when:

Theprivate key does not correspondto the certificate being used.

There is amismatchbetween the public and private key pair required for SSL handshakes.

This is a well-documented condition in Apache SSL configuration issues and explicitly covered under TLS/SSL troubleshooting sections in cybersecurity operations contexts. The Cisco CyberOps guide also notes that SSL errors with key verification usually result from "improper key/certificate pairing" rather than file corruption or missing modules.

Thus, the correct answer is:

B. The private key does not match with the SSL certificate.

The goal of the given Python code is to parse an Apache access log and extract IP addresses using regular expressions (regex). In this context, the most appropriate regex pattern to extract IPv4 addresses from log data is:

r'\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}'

This pattern matches typical IPv4 addresses, where each octet consists of 1 to 3 digits separated by periods. For example, it matches addresses like192.168.1.1or10.0.0.123. The pattern uses:

\d{1,3}to capture between 1 and 3 digits,

\.to match the dot (escaped since.is a special character in regex),

repeated 4 times with proper separation to form the full IPv4 structure.

Options A, B, and C either include incorrect syntax, improper escape sequences, or do not represent a valid IP address pattern.

This type of log analysis and pattern extraction is described in the Cisco CyberOps Associate curriculum under basic scripting and automation techniques used in log and artifact analysis.

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.

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 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 Wireshark output shows SMB protocol transactions, including NT Create AndX Response and Write AndX Response, indicating the transfer of files or objects. SMB (Server Message Block) is a protocol used for file sharing and printer access in Windows networks. The log does not indicate phishing or redirection behavior but rather normal SMB communication such as accessing files or shared resources.

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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.

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.

Comprehensive and Detailed Explanation:

The exhibit contains STIX (Structured Threat Information Expression) formatted threat intelligence indicating:

A phishing indicator related to the domain:apponline-8473.xyz

Associated malicious IP addresses:164.90.168.78and199.19.224.83

Labelled as "malicious-activity" with "xfe-threat-score-10"

Based on this:

Option B is correct: The IP addresses explicitly listed in the pattern field should be blacklisted to prevent command-and-control or malicious connections.

Option C is correct: The domainapponline-8473.xyzis also listed and flagged as involved in phishing, so DNS and firewall rules should block access to and from this domain.

Options A and E are too broad or speculative; the data specifies a specific domain, not a generic block on all emails or URLs. Option D refers to a label used for classification and not a directly actionable item.

Therefore, the correct answers are: B and C.

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.

The-hoption in theobjdumpcommand displayssection headersof an object file. According to general usage and command-line documentation, and also explained in digital forensics tools discussions in the CyberOps course, the header information includes details about the name, size, VMA, LMA, file offset, and alignment of each section in the object file. This helps analysts understand how data is stored and organized within compiled files during forensic examinations.

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.

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 PowerShell cmdlet Get-Content reads content line-by-line from a file and is commonly used for processing logs or large text files. When combined with Select-String, it can search for specific patterns (such as "ERROR" or "SUCCESS") within those lines and return a collection of matching objects, including metadata like line number and line content.

Option D uses:

Get-Content –Path: Correct syntax to read the log file from a UNC path.

Select-String “ERROR”, “SUCCESS”: Searches for these terms in each line and returns matching lines as structured output.

The other options (A, B, C) use non-existent or incorrect cmdlets/parameters such as Get-Content-Folder, –ifmatch, –Directory, which are invalid in PowerShell.

Comprehensive and Detailed Explanation:

The log entry contains the following key elements:

The timestamp:(04/Jan/2022:20:18:06 +0000)

HTTP method and URI:"GET /%60%60%60%60%60%60/ HTTP/2.0"

HTTP status code:404

User-Agent:Mozilla/5.0 ... Firefox/95.0

The status code404indicates that the requested resource was not found on the server. This is a standard HTTP response that signifies the server could not locate the requested URI (in this case, likely due to a malformed or invalid path/\`````/, where%60is the URL-encoded form of the backtick character "").

There is no clear evidence of SQL injection, WAF detection, or redirection in this log. The use of encoded backticks may suggest probing behavior, but the log does not show a definitive attack signature.

Therefore, the correct interpretation is:

Answer: D. The requested page was not found.

During the initial phase of incident response, the two key actions are:

Disconnecting the server (B) to contain the threat and prevent lateral movement or further exfiltration.

Reviewing network logs (E) to understand the timeline and scope of the attack.

These are emphasized in the containment and detection stages of the incident response lifecycle outlined in NIST 800-61 and covered in the Cisco CyberOps training.

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The combination of CPU spikes, disk usage peaks, and fluctuating PageFile.sys indicates excessive virtual memory paging, which may be a sign of malicious memory or file access behavior. PageFile.sys is part of the virtual memory system, and analyzing it can reveal which processes or payloads are consuming unusual amounts of memory, especially during exfiltration events.

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 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.

Comprehensive and Detailed Explanation:

The log entries show repeated SSH login attempts for various invalid usernames (e.g., admin, phoenix, rainbow, test, user, etc.) from different source ports. These are clear signs of a brute-force attack—an automated process trying multiple usernames and passwords in hopes of gaining access.

Mitigating such attacks includes:

Implementing account lockout policies (e.g., locking an account after several failed login attempts).

Enabling Multi-Factor Authentication (MFA) to ensure that password guessing alone is insufficient for account access.

Therefore, the correct answer is:

D. Brute-force attack; implement account lockout policies and roll out MFA.

The incident stems from a policy-level issue rather than a technical vulnerability. According to incident response best practices, the priority should be to review and update firewall rules and ensure that the network security policy aligns with the principle of least privilege and correct access segmentation.

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.

Theroot cause analysisin incident response focuses on identifying theinitial trigger or root causeof the incident to understand how it started and how to prevent recurrence. In this scenario, thephishing email sent to the victim(A) is the initial trigger that led to the employee’s action of clicking the malvertising link, resulting in the malware download.

The other options represent later stages in the incident response cycle, such as detection (SIEM alert, cybersecurity team’s alert) or supporting evidence (email header information), but they do not address the root cause, which is thephishing email itself.

This aligns with theCyberOps Technologies (CBRFIR) 300-215 study guide, which states that identifying theinitial vector of compromiseis critical to theroot cause analysisphase of incident response (Chapter: Incident Response Techniques, page 410-412).

The XML structure shows that:

The file namestarts with:"Final Report"

The file extensionequals:"doc.exe"

Together, this forms"Final Report.doc.exe"— a knowndouble-extensiontechnique used todisguise executablesas benign documents. This is a red flag in email forensics, commonly linked tomalware distribution, and explicitly covered in the Cisco CyberOps study material as a typicalevasion methodfor malicious attachments.

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.

Cisco Firepower Management Center (FMC), when configured with Snort rules, classifies attacks with signature categories such as FILE-OFFICE for Microsoft Office-based exploits. One of the critical threats involving Microsoft Office is a known vector involving Microsoft Graphics, which attackers exploit forremote code execution (RCE). RCE vulnerabilities enable attackers to execute arbitrary commands or code on the target machine—making this classification high-severity.

The alert "FILE-OFFICE Microsoft Graphics remote code execution attempt" is consistent with what Cisco and Snort define for such threats and appears in rulesets addressing vulnerabilities like CVE-2017-0001.

This behavior is consistent withmalicious macro activity. A PowerShell process being spawned fromwinword.exeviacmd.exestrongly indicates execution of an embedded script. Cisco recommends containment as a critical next step:

"Contain the threat as soon as malicious behavior is observed to prevent lateral movement or additional compromise".

In therecovery phase, the goal is to restore affected systems to normal operations and ensure the threat has been completely eradicated. According to the CyberOps Associate guide:

"This phase may include restoring data from clean backups, replacing compromised systems, and the re-installation of the Operating System (OS) and applications".

Also:

"During recovery, scanning hosts with updated antivirus and removing vulnerabilities ensures systems do not get reinfected".