300-215 Sample Questions Answers

Steganography is the anti-forensics technique of hiding malicious content within seemingly innocent files, such as image, audio, or video files. The goal is to conceal data or code in a way that avoids suspicion and detection, thereby making traditional security inspection tools ineffective unless they are explicitly designed to detect hidden data within media files.

Steganography differs from encryption because it does not simply make data unreadable; it hides the existence of the data itself. It is commonly used in cyber operations to hide command-and-control instructions or to exfiltrate sensitive information in covert ways.

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.

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.

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.

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.

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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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".

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 aSYN 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.

Thecountermeasurefor this scenario, as highlighted in theCyberOps Technologies (CBRFIR) 300-215 study guideunderNetwork-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.

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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The root cause analysis report’s main goal is to identify what allowed the ransomware to successfully infect systems. The Cisco CyberOps Associate guide emphasizes the importance of uncovering and mitigating the actual vulnerabilities that were exploited during an incident. These could include outdated software, unpatched systems, or poor access control. While understanding the encryption technique or C2 server is helpful for threat intelligence, it does not address the root cause.

The guide states:

"Effective IR helps professionals to leverage the information collected from a security incident to better understand the intrusion and its functionality… this data helps the security team to be better prepared and equipped to handle future incidents".

Identifying the exploited vulnerabilities enables future prevention strategies such as patch management, configuration hardening, and reducing attack surfaces.

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Volatility is an open-source memory forensics tool specifically designed for memory analysis. It allows forensic investigators to inspect memory dumps for running processes, hidden processes, injected code, and malicious activity in memory.

As per the Cisco CyberOps Associate study guide, “Volatility helps security professionals with both incident response and malware analysis. It can identify processes, registry artifacts, network connections, and memory-resident malware”.

While Memoryze (D) is also a memory analysis tool, Volatility is the more recognized, command-line driven tool used widely in industry and is directly highlighted in the curriculum.

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.

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

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 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:

From the exhibit, Cisco Secure Malware Analytics (formerly Threat Grid) has captured outbound HTTP POST communication to the IP address 51.38.124.206 on port 80. This destination is highlighted in the analysis under “Outbound HTTP POST Communications,” indicating exfiltration behavior or command-and-control (C2) signaling.

Key indicators:

The report shows that binary data was POSTed to this IP.

The source system generated 22 packets and sent 6,192 bytes.

The system has flagged the behavior with a severity of 25 and confidence of 25—suggesting that this is an IoC worth acting on.

Therefore, the artifacts suggest that the destination IP 51.38.124.206 is involved in malicious activity, and the correct answer is:

Answer: A. Destination IP 51.38.124.206 is identified as malicious.

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.

This STIX (Structured Threat Information eXpression) JSON snippet provides two key elements relevant for IOC (Indicator of Compromise) analysis:

The indicator pattern shows a suspicious URL:→ "pattern": "[url:value = 'http://x4z9rb.cn/4712/']" This is the actual IOC that can be used for detection.

The type of object that the indicator relates to:→ "type": "malware"→ "name": "x4z9arb backdoor"This indicates the nature of the threat associated with the IOC is malware.

Therefore, the threat is "malware" and the associated indicator (IOC) is the URL: http://x4z9rb.cn/4712/

Option A correctly captures both the IOC category ("malware") and the indicator value ("http://x4z9rb.cn/4712/").

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 goal of an incident response plan (IRP) is to provide structured procedures for responding to cybersecurity incidents in a way that limits damage, contains the threat, and ensures business continuity. As outlined in the NIST SP 800-61 and Cisco CyberOps Associate study guide, containment and minimizing the impact of incidents is the primary goal of an IRP.

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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.

According to theCyberOps Technologies (CBRFIR) 300-215 study guidecurriculum, command-and-control (C2) communication is a strong indicator that a system has already been compromised and is actively under the control of an attacker. Sudden outbound traffic to high-risk regions and resolution of known malicious domains are high-confidence signs of an active threat. Therefore, prioritizing detection and disruption of this outbound traffic is critical to prevent further damage or data exfiltration.

While monitoring vulnerability exploitation (B) and gathering port scan data (D) are also valuable, they are more preventive or forensic in nature. The most immediate threat—and therefore the top priority—is stopping active C2 communications.

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 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.

Ghidrais a free and open-source software reverse engineering (SRE) suite developed by the NSA. It includes disassembly, decompilation, and debugging tools specifically designed for analyzing malware and other compiled programs.

The Cisco CyberOps guide referencesGhidraas a top tool for reverse engineering binary files during malware analysis tasks, making it ideal for understanding malicious code behavior at a deeper level.

The alert shown is based on aSnort rulefor aUnicode directory traversal attack against IIS web servers(Microsoft platform). The key detail here is the payload content"../..%c0%af../"which is a classic IIS-specific exploit related toCVE-2000-0884.

Since the company only usesUnix systems, they arenot vulnerableto this IIS-specific attack. Therefore, these alerts are triggered by irrelevant traffic or misapplied signatures, resulting inFalse Positives.

As defined in the Cisco CyberOps guide:

“False Positive: an alert is generated for traffic that is not actually malicious or relevant to the protected environment”.

If IPS and SIEM logs do not give enough insight into a file's behavior, the next logical step is to review theAntivirus solutionlogs. These logs often provide detailed behavior analytics such as:

File actions and access patterns

Registry modifications

File execution history

The Cisco CyberOps guide emphasizes AV logs as critical forensic artifacts for understanding endpoint-based infections, especially when beaconing or suspicious activity is suspected.