CAS-004 Exam Dumps - CompTIA CASP Questions and Answers

DMARC (Domain-based Message Authentication, Reporting and Conformance) and SPF (Sender Policy Framework) are two mechanisms that can help detect and prevent email spoofing, which is the creation of email messages with a forged sender address. DMARC allows a domain owner to publish a policy that specifies how receivers should handle messages that fail authentication tests, such as SPF or DKIM (DomainKeys Identified Mail). SPF allows a domain owner to specify which mail servers are authorized to send email on behalf of their domain. By checking the DMARC and SPF records of the sender’s domain, a receiver can verify if the email is from a legitimate source or not. Verified References:

https://en.wikipedia.org/wiki/Email_spoofing

https://en.wikipedia.org/wiki/DMARC

https://en.wikipedia.org/wiki/Sender_Policy_Framework

Preparation is the process that can be used to identify potential prevention recommendations after a security incident, such as a ransomware attack. Preparation involves planning and implementing security measures to prevent or mitigate future incidents, such as by updating policies, procedures, or controls, conducting training or awareness campaigns, or acquiring new tools or resources. Detection is the process of discovering or identifying security incidents, not preventing them. Remediation is the process of containing or resolving security incidents, not preventing them. Recovery is the process of restoring normal operations after security incidents, not preventing them. Verified References: https://www.comptia.org/blog/what-is-incident-response https://partners.comptia.org/docs/default-source/resources/casp-content-guide

Cipher feedback (CFB) is a mode of operation for block ciphers that allows them to encrypt streaming data. CFB uses an initialization vector (IV) and a block cipher to generate a keystream that is XORed with the plaintext to produce the ciphertext. CFB has low latency because it can encrypt each byte or bit of plaintext as soon as it arrives, without waiting for a full block. CFB is suitable for streaming data because it does not require padding or block synchronization.

B. Cipher block chaining message authentication code (CBC-MAC) is a mode of operation for block ciphers that provides both encryption and authentication. CBC-MAC uses an IV and a block cipher to encrypt the plaintext and generate a MAC value that is appended to the ciphertext. CBC-MAC has high latency because it requires the entire message to be processed before generating the MAC value. CBC-MAC is not suitable for streaming data because it requires padding and block synchronization.

C. Cipher block chaining (CBC) is a mode of operation for block ciphers that provides encryption only. CBC uses an IV and a block cipher to encrypt each block of plaintext by XORing it with the previous ciphertext block. CBC has high latency because it requires a full block of plaintext before encryption. CBC is not suitable for streaming data because it requires padding and block synchronization.

D. Electronic codebook (ECB) is a mode of operation for block ciphers that provides encryption only. ECB uses a block cipher to encrypt each block of plaintext independently. ECB has low latency because it can encrypt each block of plaintext as soon as it arrives. However, ECB is not suitable for streaming data because it requires padding and block synchronization. Moreover, ECB is insecure because it does not use an IV and produces identical ciphertext blocks for identical plaintext blocks.

Input validation is a technique that checks the user input for any errors, malicious data, or unexpected values before processing it by the application. Input validation can prevent many common web application attacks, such as:

SQL injection, which exploits a vulnerability in the application’s database query to execute malicious SQL commands.

Cross-site scripting (XSS), which injects malicious JavaScript code into the application’s web page to execute on the client-side browser.

Directory traversal, which accesses files or directories outside of the intended scope by manipulating the file path.

In this case, the security engineer should recommend input validation as the best mitigation technique, because it would:

Prevent the exfiltration of a company report by validating the file parameter in the URL and ensuring that it matches a predefined list of allowed files or formats.

Enhance the security of the web application by filtering out any malicious or invalid input from users or attackers.

Be more effective and efficient than other techniques, such as firewall, WAF (Web Application Firewall), or DLP (Data Loss Prevention), which may not be able to detect or block all types of web application attacks.

The administrator should use SAN certificates to support multiple domain names while minimizing the amount of certificates needed. SAN stands for Subject Alternative Name, which is an extension of a certificate that allows it to include multiple fully-qualified domain names (FQDNs) within the same certificate. For example, a SAN certificate can secure www.example.com, www.example.net, and mail.example.org with one certificate. SAN certificates can reduce the cost and complexity of managing multiple certificates for different domains. SAN certificates can also support wildcard domains, such as *.example.com, which can cover any subdomain under that domain. Verified References:

https://www.techtarget.com/searchsecurity/definition/Subject-Alternative-Name

https://www.techtarget.com/searchsecurity/definition/wildcard-certificate

https://www.nexcess.net/help/what-is-a-multi-domain-ssl-certificate/

The SIEM events show that powershell.exe was executed on multiple endpoints with an outbound connection to 40.90.23.154, which is an IP address associated with malicious activity. This could indicate a malware infection or a command-and-control channel. The best response action is to configure the forward proxy to block 40.90.23.154, which would prevent further communication with the malicious IP address. Disabling powershell.exe on all endpoints may not be feasible or effective, as it could affect legitimate operations and not remove the malware. Restarting Microsoft Windows Defender may not detect or stop the malware, as it could have bypassed or disabled it. Disabling local administrator privileges on the endpoints may not prevent the malware from running or communicating, as it could have escalated privileges or used other methods. Verified References: https://www.comptia.org/blog/what-is-a-forward-proxy https://partners.comptia.org/docs/default-source/resources/casp-content-guide

Field masking is a technique that hides or obscures part of the information in a data field, such as a password, credit card number, or social security number. Field masking can be used to protect sensitive or confidential data from unauthorized access or disclosure, while still allowing authorized users to view or verify the data.

Field masking should be implemented to authenticate employees who call in remotely by allowing the help desk staff to view partial information about employees, because field masking would:

Enable the help desk staff to verify the identity of the employees by asking them to provide some characters or digits from their data fields, such as their employee ID or email address.

Prevent the help desk staff from viewing the full information about employees, which may be considered sensitive and subject to privacy regulations or policies.

Reduce the risk of data leakage, theft, or misuse by limiting the exposure of sensitive data to only those who need it.

A downgrade attack is a type of man-in-the-middle attack that forces two hosts to use an older or weaker version of the TLS protocol or its parameters. The attacker does this by replacing or deleting the STARTTLS command or exploiting the compatibility features of the protocol. The purpose of the attack is to create a pathway for enabling a cryptographic attack that would not be possible in case of a connection that is encrypted over the latest version of TLS protocol. The IOC shows that most client connections are renegotiated after establishing the connections, which could indicate that an entity is performing downgrade attacks on path by interfering with the initial handshake and making the client and server agree on a lower version of TLS or a weaker cipher suite. Verified References:

https://en.wikipedia.org/wiki/Downgrade_attack

https://crypto.stackexchange.com/questions/10493/why-is-tls-susceptible-to-protocol-downgrade-attacks

https://venafi.com/blog/preventing-downgrade-attacks/

Law enforcement officials informed an organization that an investigation has begun. Which of the following is the FIRST step the organization should take?

Initiate a legal hold.

Refer to the retention policy

Perform e-discovery.

Review the subpoena

Answer: A

A legal hold is a process by which an organization instructs its employees or other relevant parties to preserve specific data for potential litigation. A legal hold is triggered when litigation is reasonably anticipated, such as when law enforcement officials inform an organization that an investigation has begun. The first step the organization should take is to initiate a legal hold to ensure that relevant evidence is not deleted, destroyed, or altered. A legal hold also demonstrates the organization’s good faith and compliance with its duty to preserve evidence. Verified References:

https://percipient.co/litigation-hold-triggers-and-the-duty-to-preserve-evidence/

https://www.everlaw.com/blog/ediscovery-best-practices/guide-to-legal-holds/

An ISA, or interconnection security agreement, is a document that should be required to set up a dedicated VPN between two entities that provide specialized help desk services. An ISA defines the technical and security requirements for establishing, operating, and maintaining a secure connection between two or more organizations. An ISA also specifies the roles and responsibilities of each party, the security controls and policies to be implemented, the data types and classifications to be exchanged, and the incident response procedures to be followed.

References: [CompTIA CASP+ Study Guide, Second Edition, page 36]

The change control board (CCB) is a committee that consists of subject matter experts and managers who decide whether to implement proposed changes to a project. The change control board is part of the change management plan, which defines the roles and processes for managing change within a team or organization. The change control board must review and approve a submission for any change request that affects the scope, schedule, budget, quality, or risks of the project. The change control board evaluates the impact and benefits of the change request and decides whether to accept, reject, or defer it.

A. The implementation engineer requesting direct approval from the systems engineer and the Chief Information Security Officer is not a correct process for requesting updates or corrections to the client’s systems, because it bypasses the change control board and the project manager. This could lead to unauthorized changes that could compromise the project’s objectives and deliverables.

C. The information system security officer providing the systems engineer with the system updates is not a correct process for requesting updates or corrections to the client’s systems, because it does not involve the change control board or the project manager. This could lead to unauthorized changes that could introduce security vulnerabilities or conflicts with other system components.

D. The security engineer asking the project manager to review the updates for the client’s system is not a correct process for requesting updates or corrections to the client’s systems, because it does not involve the change control board. The project manager is responsible for facilitating the change management process, but not for approving or rejecting change requests.

https://www.projectmanager.com/blog/change-control-board-roles-responsibilities-processes

SaaS, or software as a service, is the solution that can best fulfill the requirements of having the lowest RTO possible, the least shared responsibility possible, and patching as a responsibility of the CSP. SaaS is a cloud service model that provides users with access to software applications hosted and managed by the CSP over the internet. SaaS has the lowest RTO (recovery time objective), which is the maximum acceptable time for restoring a system or service after a disruption, because it does not require any installation, configuration, or maintenance by the users. SaaS also has the least shared responsibility possible because most of the security aspects are handled by the CSP, such as patching, updating, backup, encryption, authentication, etc.

References: [CompTIA CASP+ Study Guide, Second Edition, pages 403-404]