350-201 Performing CyberOps Using Core Security Technologies (CBRCOR) Questions and Answers

To prevent DDoS attacks while accommodating legitimate high-volume requests from trusted services, it’s advisable to implement rate limiting. This involves setting a threshold for the number of requests that can be made to an API within a certain time frame. If this limit is exceeded, access should be temporarily blocked, and a 429 HTTP error code (“Too Many Requests”) should be returned. This allows legitimate users to be throttled rather than completely cut off, preserving functionality while protecting against abuse.

 The indicator of compromise (IOC) event triggered by the abuse of PowerShell commands and script interpreters, leading to the execution of a known malicious file, is most likely generated by an ExecutedMalware.ioc. This type of IOC is specifically designed to detect the execution of malicious software on a system, which aligns with the scenario described4.

After isolating the affected workstation in a malware incident, the next step in the investigation is to inspect the registry entries for recently executed files. This can provide clues about the malware’s actions and potential persistence mechanisms. It’s a critical step in understanding the scope of the breach and the methods used by the attacker

When multiple shortcuts in the system’s startup folder redirect to malicious URLs, the next step is to identify all affected systems. This is crucial to understand the scope of the issue and to prevent further spread of the malware. Removing the shortcuts (option A) is a necessary step but should be done after identifying all affected systems to ensure a comprehensive response. Checking the audit logs (option B) and investigating the malicious URLs (option D) are also important steps, but they come after identifying all systems that might be compromised

 When an email attachment’s hash has no history in open source intelligence databases, the next step is to obtain a copy of the file for analysis in a controlled environment, known as a sandbox. This allows the analyst to observe the behavior of the file without risking the security of the network or systems

After using antivirus and malware removal tools, if abnormal processes are still occurring, the engineer should analyze the components of the infected hosts and their associated business services. This step is crucial to understand the scope of the infection, determine how the malware is affecting the system, and identify any changes made by the malware. This analysis will help in planning the subsequent steps for cleaning the infected host and restoring its functionality1.

The command that was executed in PowerShell to generate the log shown in the exhibit is Get-WinEvent -ListLog* -ComputerName localhost. This command is used to list all event logs and their properties on the local computer. The inclusion of -ComputerName localhost specifies that the command should target the local machine, which is consistent with the details provided in the log exhibit. The output format displayed in the exhibit, showing details such as “Max (K)”, “Retain”, “OverflowAction”, “Entries”, and “Log”, matches the typical output of the Get-WinEvent cmdlet when used with the -ListLog parameter.

References :=

PowerShell documentation on the Get-WinEvent cmdlet.

Best practices for using PowerShell to manage Windows event logs.

The STIX (Structured Threat Information eXpression) in the context of the exhibit indicates a scenario where a Google Chrome extension is initiating direct IP connections using the WebSocket protocol, and the payloads are obfuscated and unreadable. This behavior is suspicious and suggests that the extension could be a front for malware that is using encrypted channels to communicate with a command and control server. The use of WebSockets and the obfuscation of payloads are common tactics used by malware authors to evade detection and maintain persistent control over compromised systems. The fact that the payloads cannot be decoded or read as UTF-8 text further supports the likelihood of malicious activity, as legitimate extensions would not typically need to obfuscate their communications.

References :=

STIX/TAXII is a framework for sharing cyber threat intelligence, which would include indicators of such suspicious activities1.

Understanding the implications of obfuscated payloads in network traffic, as described in cybersecurity resources23.

 A Security Information and Event Management (SIEM) tool is primarily used to collect and analyze security data from various sources, such as network devices and servers, and then produce alerts based on this analysis. SIEM tools aggregate and correlate data to identify patterns that may indicate a security incident, allowing organizations to respond to threats more effectively.

The Wireshark traffic capture exhibits a pattern where a single source IP address is sending a series of SYN packets to a single destination IP address. This pattern is indicative of a SYN flood attack, which is a form of Denial-of-Service (DoS) attack. In a SYN flood attack, the attacker exploits the TCP handshake mechanism by sending a flood of SYN packets to the target’s IP address. Theattacker does not complete the handshake with an ACK after receiving a SYN-ACK from the server, leaving connections half-open and eventually exhausting the server’s resources, which can lead to denial of service.

References:

The Cisco CyberOps curriculum, particularly the courses on Performing CyberOps Using Cisco Security Technologies (CBRCOR), would cover the identification and analysis of network threats, including SYN flood attacks.

Cisco’s official certification resources for the CyberOps Associate level would provide detailed information on various network threats and how to mitigate them, including the mechanisms of a SYN flood attack.

The error message “The Group Policy Client service failed to logon – Access is denied” suggests a problem with user permissions, which are managed by group policies in Windows environments. The unexpected modifications to system settings further indicate that an unauthorized user or process has gained higher-level permissions than originally assigned. This scenario is characteristic of an elevation of privileges breach, where an attacker gains elevated access to resources that are normally protected from an application or user. This can be achieved through various methods, including exploiting software vulnerabilities, configuration errors, or using social engineering techniques.

References:

Cisco’s CyberOps Using Core Security Technologies course would cover the identification and handling of security breaches, including elevation of privileges.

The CyberOps Associate certification materials provide detailed information on various types of breaches and their indicators.

Cisco’s official blogs and learning resources offer insights into the latest cybersecurity threats and how to mitigate them, including privilege escalation incidents.

The breach described could have been prevented by integrating security practices into the development lifecycle, known as SecDevOps. This approach includes continuous security checks and vulnerability assessments during the development stages, which would likely have identified the vulnerability before the code was deployed.

Following behavioral analysis in a controlled laboratory, the next step in the malware analysis process is to perform static and dynamic code analysis of the specimen. Static analysis involves examining the malware without executing it, while dynamic analysis involves observing the malware’s behavior in a controlled environment. These analyses provide deeper insights into the malware’s capabilities and intentions2.

The combination of increased incoming spam emails and web scraping alerts suggests a phishing attempt. Phishing is a type of social engineering attack where attackers send fraudulent messages designed to trick individuals into revealing sensitive information or deploying malicious software. Web scraping can be used to gather email addresses for such campaigns

The script needs to be changed to include a validation function that checks if the usernames meet the specified conditions. The correct function name should reflect its purpose, so validate_user is appropriate. The function should check that the username has a minimum length of 3, only contains letters, numbers, dots, and underscores, and does not begin with a number. If the username does not meet these conditions, the function should return False or raise an error.

Here’s an updated version of the script with the necessary changes:

Python

import re

def validate_user(username, minlen=3):

if type(username) != str or len(username) < minlen:

return False

if not re.match("^[a-zA-Z._][a-zA-Z0-9._]*$", username):

return False

return True

AI-generated code. Review and use carefully. More info on FAQ.

This function will now properly enforce the company’s user creation policy by validating the usernames according to the given rules.

When an engineer discovers that payments have been sent to the wrong recipient due to a SaaS tool being down, the first step should be to contact the incident response team to inform them of a potential breach. This allows for an immediate investigation into the incident and the implementation of measures to mitigate any potential damage5.

The bash command grep -i “yellow” colors.txt will print all lines from the “colors.txt” file containing the non case-sensitive pattern “Yellow”. The -i option in the grep command is used to ignore case distinctions in both the pattern and the input files, allowing it to match both “Yellow”, “yellow”, “YELLOW”, etc.

When there is a significant load of network activity from locations outside the organization’s service area, especially at unusual times, it is important to investigate the nature of this traffic. The engineer should review the logs from network monitoring tools like StealthWatch or SIEM to identify the access points through which the traffic is coming. Understanding the services being accessed during these hours and cross-correlating with other source events can help in determining whether the activity is legitimate or if it indicates a potential security threat1

Wireshark decrypts TLS network traffic by using a key log file that contains per-session secrets1. This method is effective even when Diffie-Hellman (DH) key exchange is used, which is common in modern encrypted communications. The key log file is typically generated by applications like web browserswhen the SSLKEYLOGFILE environment variable is set. This file records the necessary per-session secrets that Wireshark can then use to decrypt the traffic1.

It’s important to note that while this method is universal and works across different TLS versions, including TLS 1.3, other methods such as using an RSA private key are limited to certain conditions and do not work with TLS 1.3 or when (EC)DHE cipher suites are selected1. Therefore, the key log file method is the most reliable and widely applicable approach for decrypting TLS in Wireshark.

A European-based advertisement company that collects tracking information from partner websites must adhere to the General Data Protection Regulation (GDPR). GDPR is the standard that governs data protection and privacy in the European Union and the European Economic Area. It provides guidelines on how personal data should be collected, processed, and stored, ensuring that individuals’ data is protected and that companies are transparent about their data handling practices

 The creation of privileged user accounts in the Active Directory that coincide with suspicious network traffic suggests a network compromise. This type of activity is often indicative of an attacker gaining sufficient access to create accounts with elevated privileges, which can be used for further malicious activities within the network. The cross-correlation of events from other sources that align with the timing of these account creations strengthens the case for a compromised network. This scenario is consistent with tactics used by attackers to maintain persistence and establish control over network resources for ongoing exploitation1.

References:

The Performing CyberOps Using Cisco Security Technologies (CBRCOR) course covers the fundamentals of cybersecurity operations, including the identification and analysis of security incidents and network compromises1.

The Cisco Certified CyberOps Associate certification provides knowledge on monitoring, detecting, and responding to cybersecurity threats, which includes understanding the signs of a compromised network2

 The data format being used in the exhibit is XML (Extensible Markup Language). This can be determined by the presence of tags enclosed in angle brackets (<>), which define the start and end of an element, as well as the hierarchical structure that organizes the data within nested elements. In this case, there are “employee” elements nested within an “employees” root element, each containing “lastname” and “firstname” child elements with corresponding closing tags.

References:

Cisco’s training on Performing CyberOps Using Cisco Security Technologies would cover data formats like XML as part of understanding how to handle and analyze security data.

The official Cisco Certified CyberOps Associate certification resources would include information on various data formats encountered in cybersecurity operations.

 In Cisco Secure Network Analytics (Stealthwatch), when an engineer needs to analyze the top data transmissions to identify significant anomalies in traffic within a host group, the Top Conversations tool is used. This tool provides a detailed view of the communication between hosts, showing which pairs of hosts are exchanging the most data. By examining the top conversations, the engineer can pinpoint which specific data flows are contributing to the anomaly and take appropriate action.

The Top Conversations tool is particularly useful for this task because it focuses on the interactions between hosts, rather than just the volume of traffic (Top Ports), the individual hosts themselves (Top Hosts), or the peers (Top Peers) involved in the network communications. It allows for a more granular analysis of the network traffic, which is essential for identifying and addressing anomalies.

 According to the NIST incident response handbook, after detecting a ransomware outbreak and notifying the affected parties, the next step is to eradicate the malicious software from the infected machines. This involves removing the ransomware and any associated malware to prevent further encryption or spread of the infection3

 When a SIEM tool alerts about a VPN connection attempt from an unusual location, and it is validated that an attacker has installed a remote access tool on a user’s laptop, the immediate next step is to block the source IP from the firewall. This action prevents the attacker from using that IP address to establish a connection to the network, thereby containing the threat and preventing further unauthorized access2.

 Upon receiving an alert that a contractor has downloaded multiple documents from the company’s confidential document management folder, the security manager should report the incident to the incident response team. This team is responsible for investigating the incident, assessing the impact, and determining the appropriate response to the unauthorized access

Hardening machine images for deployment reduces the attack surface by eliminating unnecessary services, closing open network ports, removing unused software, and applying security configurations. This process minimizes the number of potential vulnerabilities that can be exploited by attackers3.

The stage of the threat kill chain indicated by the URIs of inbound web requests from known malicious Internet scanners is reconnaissance. During this stage, attackers are gathering information about the target system, looking for vulnerabilities or weak points that can be exploited. The URIs provided in the exhibit suggest attempts to discover administrative interfaces, exploit known vulnerabilities, and test for common web application weaknesses such as cross-site scripting (XSS) and SQL injection. These activities are characteristic of the reconnaissance phase, where attackers are probing and mapping out the target environment to plan their subsequent moves.

 When addressing detected vulnerabilities, it is crucial to first evaluate the potential service disruption and associated risks before prioritizing patches. This approach ensures that the most critical services remain operational and that the patches are applied in a manner that minimizes impact on business operations. It is important to consider the severity of the vulnerabilities, the importance of the affected systems, and the potential consequences of applying patches, which may require system reboots or could lead to compatibility issues with other applications123.

References:

Cisco’s Performing CyberOps Using Cisco Security Technologies (CBRCOR) course provides guidance on cybersecurity operations, including vulnerability management and mitigation strategies1.

The CBRCOR Exam Topics outline the importance of evaluating the security posture of an asset and determining patching recommendations based on scenarios, which aligns with the recommended mitigation step of evaluating service disruption and associated risk2.

Industry best practices for vulnerability management also emphasize the need to assess the impact of patches and to prioritize them based on the risk to the organization

 Upon receiving an alert of a zero-day vulnerability, the first step an engineer should take is to initiate a triage meeting to acknowledge the vulnerability and assess its potential impact2. This step is crucial for understanding the severity of the vulnerability, determining the scope of affected systems, and deciding on the subsequent actions to mitigate the risk. It involves gathering the relevant stakeholders and security experts to evaluate the threat and develop a response plan2.

The first security threat that should be mitigated when installing a new application server for IP phones is the attack using default accounts. Default accounts often have preset usernames and passwords that are widely known and can be easily exploited by attackers. It is crucial to change these default credentials to prevent unauthorized access

Including a step to “Take a Snapshot” in the SOAR solution workflow is the most effective action to accomplish the goal of allowing security analysts to be proactive and anticipate attacks. By capturing the endpoint state when a threat is identified, analysts can contain the threat and have a detailed record of the system at the time of the incident. This enables a thorough analysis of the threat, which is essential for understanding attack patterns, identifying potential vulnerabilities, and developing strategies to prevent future incidents.

The other options do not directly contribute to the goal of enabling proactive analysis:

A. Exclude the step “BAN malicious IP”: This would allow threats to persist in the system, potentially causing more harm.

C. Exclude the step “Check for GeoIP location”: GeoIP location is valuable for assessing the risk based on asset criticality and should not be excluded.

D. Include a step “Reporting”: While reporting is important, it does not directly aid in the proactive analysis of threats.

By taking snapshots for analysis, the security team can better understand the nature of the threats and refine their detection and response mechanisms accordingly. This proactive approach is crucial for staying ahead of cyber threats and ensuring the security of the organization’s assets.