CompTIA CS0-003 Online Practice Questions and Exam Preparation

CompTIA CS0-003 Online Questions & Answers

• Question 121:

  A security analyst wants to capture large amounts of network data that will be analyzed at a later time. The packet capture does not need to be in a format that is readable by humans, since it will be put into a binary file called "packetCapture." The capture must be as efficient as possible, and the analyst wants to minimize the likelihood that packets will be missed.

  Which of the following commands will best accomplish the analyst's objectives?

  A. tcpdump -w packetCapture
  B. tcpdump -a packetCapture
  C. tcpdump -n packetCapture
  D. nmap -v > packetCapture
  E. nmap -oA > packetCapture
  A. tcpdump -w packetCapture

  ---

  Explanation

  The tcpdump command is a network packet analyzer tool that can capture and display network traffic. The -w option specifies a file name to write the captured packets to, in a binary format that can be read by tcpdump or other tools later.

  This option is useful for capturing large amounts of network data that will be analyzed at a later time, as the question requires. The packet capture does not need to be in a format that is readable by humans, since it will be put into a binary file called " . The capture must be as efficient as possible, and the -w option minimizes the processing and output overhead of tcpdump, reducing the likelihood that packets will be missed.

• Question 122:

  During an investigation, an analyst discovers the following rule in an executive's email client:

  

  The executive is not aware of this rule.

  Which of the following should the analyst do first to evaluate the potential impact of this security incident?

  A. Check the server logs to evaluate which emails were sent to <someaddress@domain,com>.
  B. Use the SIEM to correlate logging events from the email server and the domain server.
  C. Remove the rule from the email client and change the password.
  D. Recommend that the management team implement SPF and DKIM.
  C. Remove the rule from the email client and change the password.

• Question 123:

  A company is launching a new application in its internal network, where internal customers can communicate with the service desk. The security team needs to ensure the application will be able to handle unexpected strings with anomalous formats without crashing.

  Which of the following processes is the most applicable for testing the application to find how it would behave in such a situation?

  A. Fuzzing
  B. Coding review
  C. Debugging
  D. Static analysis
  A. Fuzzing

  ---

  Explanation

  Fuzzing is a process used to test applications by inputting unexpected or random data to see how the application behaves. This method is particularly effective in identifying vulnerabilities such as buffer overflows, input validation errors, and other anomalies that could cause the application to crash or behave unexpectedly. By using fuzzing, the security team can ensure the new application is robust and capable of handling unexpected strings with anomalous formats without crashing.

• Question 124:

  The security team at a company, which was a recent target of ransomware, compiled a list of hosts that were identified as impacted and in scope for this incident. Based on the following host list:

  

  Which of the following systems was most pivotal to the threat actor in its distribution of the encryption binary via Group Policy?

  A. SQL01
  B. WK10-Sales07
  C. WK7-Plant01
  D. DCEast01
  E. HQAdmin9
  D. DCEast01

  ---

  Explanation

  Since the binary was distributed via group policy, gaining access to the domain controller would be pivotal.

• Question 125:

  Which of the following techniques would be best to provide the necessary assurance for embedded software that drives centrifugal pumps at a power Plant?

  A. Containerization
  B. Manual code reviews
  C. Static and dynamic analysis
  D. Formal methods
  D. Formal methods

  ---

  Explanation

  According to the CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition1, the best technique to provide the necessary assurance for embedded software that drives centrifugal pumps at a power plant is formal methods. Formal methods are a rigorous and mathematical approach to software development and verification, which can ensure the correctness and reliability of critical software systems. Formal methods can be used to specify, design, implement, and verify embedded software using formal languages, logics, and tools 1.

  Containerization, manual code reviews, and static and dynamic analysis are also useful techniques for software assurance, but they are not as rigorous or comprehensive as formal methods. Containerization is a method of isolating and packaging software applications with their dependencies, which can improve security, portability, and scalability. Manual code reviews are a process of examining the source code of a software program by human reviewers, which can help identify errors, vulnerabilities, and compliance issues. Static and dynamic analysis are techniques of testing and evaluating software without executing it (static) or while executing it (dynamic), which can help detect bugs, defects, and performance issues 1.

• Question 126:

  A security analyst is reviewing the logs of a web server and notices that an attacker has attempted to exploit a SQL injection vulnerability.

  Which of the following tools can the analyst use to analyze the attack and prevent future attacks?

  A. A web application firewall
  B. A network intrusion detection system
  C. A vulnerability scanner
  D. A web proxy
  A. A web application firewall

  ---

  Explanation

  A web application firewall (WAF) is a tool that can protect web servers from attacks such as SQL injection, cross-site scripting, and other web-based threats. A WAF can filter, monitor, and block malicious HTTP traffic before it reaches the web server. A WAF can also be configured with rules and policies to detect and prevent specific types of attacks.

  References:

  CompTIA CySA+ Study Guide: Exam CS0-002, 2nd Edition, Chapter 3, "Security Architecture and Tool Sets", page 91

  CompTIA CySA+ Certification Exam Objectives Version 4.0, Domain 1.0 "Threat and Vulnerability Management", Objective 1.2 "Given a scenario, analyze the results of a network reconnaissance", Sub-objective "Web application attacks", page 9 CompTIA CySA+ Study Guide: Exam CS0-002, 2nd Edition : CompTIA CySA+ Certification Exam Objectives Version 4.0.pdf)

• Question 127:

  An organization announces that all employees will need to work remotely for an extended period of time. All employees will be provided with a laptop and supported hardware to facilitate this requirement. The organization asks the information security division to reduce the risk during this time.

  Which of the following is a technical control that will reduce the risk of data loss if a laptop is lost or stolen?

  A. Requiring the use of the corporate VPN
  B. Requiring the screen to be locked after five minutes of inactivity
  C. Requiring the laptop to be locked in a cabinet when not in use
  D. Requiring full disk encryption
  D. Requiring full disk encryption

  ---

  Explanation

  Full disk encryption (FDE) is a technical control that encrypts all the data on a disk drive, including the operating system and applications. FDE prevents unauthorized access to the data if the disk drive is lost or stolen, as it requires a password or key to decrypt the data. FDE can be implemented using software or hardware solutions and can protect data at rest on laptops and other devices. The other options are not technical controls or do not reduce the risk of data loss if a laptop is lost or stolen. CompTIA Cybersecurity Analyst (CySA+) Certification Exam Objectives (CS0-002), page 10;

  https://docs.microsoft.com/en-us/windows/security/information-protection/bitlocker/bitlockeroverview

• Question 128:

  A security analyst has received an incident case regarding malware spreading out of control on a customer's network. The analyst is unsure how to respond. The configured EDR has automatically obtained a sample of the malware and its signature.

  Which of the following should the analyst perform next to determine the type of malware, based on its telemetry?

  A. Cross-reference the signature with open-source threat intelligence.
  B. Configure the EDR to perform a full scan.
  C. Transfer the malware to a sandbox environment.
  D. Log in to the affected systems and run necstat.
  A. Cross-reference the signature with open-source threat intelligence.

  ---

  Explanation

  5. Specifically, it explains the meaning and function of malware signatures and how they can be used to identify malware types1, page 203. It also discusses the benefits and challenges of using open-source threat intelligence sources to enhance security analysis1, page

  211. Therefore, this is a reliable source to verify the answer to the question.

• Question 129:

  An email hosting provider added a new data center with new public IP addresses.

  Which of the following most likely needs to be updated to ensure emails from the new data center do not get blocked by spam filters?

  A. DKIM
  B. SPF
  C. SMTP
  D. DMARC
  B. SPF

  ---

  Explanation

  SPF (Sender Policy Framework) is a DNS TXT record that lists authorized sending IP addresses for a given domain. If an email hosting provider added a new data center with new public IP addresses, the SPF record needs to be updated to include those new IP addresses, otherwise the emails from the new data center may fail SPF checks and get blocked by spam filters

  References: 1: Use DMARC to validate email, setup steps 2: How to set up SPF,

  DKIM and DMARC: other mail & hosting providers providers 3: Set up SPF, DKIM, or DMARC records for my hosting email

• Question 130:

  An analyst discovers unusual outbound connections to an IP that was previously blocked at the web proxy and firewall. Upon further investigation, it appears that the proxy and firewall rules that were in place were removed by a service account that is not recognized.

  Which of the following parts of the Cyber Kill Chain does this describe?

  A. Delivery
  B. Command and control
  C. Reconnaissance
  D. Weaporization
  B. Command and control

  ---

  Explanation

  The Command and Control stage of the Cyber Kill Chain describes the communication between the attacker and the compromised system. The attacker may use this channel to send commands, receive data, or update malware. If the analyst discovers unusual outbound connections to an IP that was previously blocked, it may indicate that the attacker has established a command and control channel and bypassed the security controls.

  References:

  Cyber Kill Chain?| Lockheed Martin