312-39 Exam Dumps - Certified SOC Analyst (CSA)

Juliea, the SOC analyst, noticed large TXT and NULL payloads in the logs. This is indicative of a DNS exfiltration attempt. DNS exfiltration is a type of cyber attack where an attacker uses the DNS protocol to sneak data out of a network undetected. It typically involves the use of large TXT records, which can be used to carry data out of the network. NULL payloads can be used in this context to pad the DNS queries and make them less suspicious or to bypass security controls that inspect the content of DNS queries.

The steps involved in DNS exfiltration include:

• The attacker compromises a system within the target network.
• Malware on the compromised system encodes the data it wants to exfiltrate.
• The encoded data is split into chunks that fit into DNS query sizes.
• These chunks are sent as data in DNS queries or responses, often using TXT records.
• An external attacker-controlled server receives the DNS queries and decodes the data.

References:

• EC-Council’s Certified SOC Analyst (CSA) course material and study guides provide detailed information on various types of cyber attacks, including DNS exfiltration.
• Online resources and practice questions for the Certified SOC Analyst (CSA) exam also cover this topic and can be used to verify the answer123.
• Additional information on DNS exfiltration techniques and detection methods can be found in security blogs and articles that discuss the subject in depth456.

Web services attacks can be mitigated by filtering improper XML syntax because these attacks often exploit vulnerabilities in web services that accept XML input. XML filtering ensures that only properly formatted XML data is processed by the web service. This can prevent various forms of XML-related attacks, such as XML injection or XML External Entity (XXE) attacks, where attackers attempt to interfere with the processing of XML data.

References: The EC-Council’s Certified SOC Analyst (CSA) program covers the fundamentals of SOC operations, including the identification and validation of intrusion attempts, and the use of SIEM solutions for enhanced threat detection. The program emphasizes the importance of understanding the various types of attacks and the appropriate defensive measures, including the filtering of improper XML syntax to protect against web services attacks12.

In the Syslog protocol, severity levels are categorized from 0 to 7, with level 0 being the most severe. Level 0 indicates an “Emergency” situation which means the system is unusable. This level of severity is used for the most critical messages, often indicating a complete service or system shutdown.

References:

• EC-Council’s Certified SOC Analyst (CSA) course materials, which cover the Syslog severity levels as part of the training1.
• InfraExam 2024, Certified SOC Analyst Part 01, which includes details on Syslog severity levels2.

A DHCP Starvation Attack is a type of network attack that aims to deplete the pool of available IP addresses on the DHCP server. The attacker floods the DHCP server with fake DHCP DISCOVER messages using spoofed MAC addresses. If successful, the server will exhaust its address space, denying IP configuration to legitimate clients. This can lead to a denial of service (DoS) for new devices attempting to join the network. Additionally, the attacker may set up a rogue DHCP server to issue malicious IP configurations to clients, potentially redirecting traffic or causing further disruption1.

References: The EC-Council SOC Analyst course and study materials cover various network attacks, including DHCP Starvation Attacks. These resources provide insights into the nature of these attacks, their potential impact, and strategies for prevention and mitigation213.

The regular expression provided in the question is designed to detect patterns that are typically found in XSS (Cross-Site Scripting) attacks. Here’s a breakdown of the regex pattern:

• /((\%3C)|<) - This part of the pattern matches the encoded version of < which is %3C, or the symbol < itself. In HTML, this symbol denotes the start of a tag.
• ((\%69)|i|(\%49)) - This matches the encoded version of i which is %69, the lowercase i, or the encoded version of I which is %49.
• ((\%6D)|m|(\%4D)) - This matches the encoded version of m which is %6D, the lowercase m, or the encoded version of M which is %4D.
• ((\%67)|g|(\%47)) - This matches the encoded version of g which is %67, the lowercase g, or the encoded version of G which is %47.
• [^\n]+ - This part of the pattern matches one or more characters that are not a newline character.
• ((\%3E)|>) - This matches the encoded version of > which is %3E, or the symbol > itself, denoting the end of an HTML tag.

The combination of these patterns is looking for a string that resembles an HTML img tag, which is a common vector for XSS attacks. XSS attacks involve injecting malicious scripts into webpages viewed by other users, exploiting the trust a user has for a particular site. XSS attacks can occur when a web application uses unsanitized user input in the output it generates.

References: The EC-Council’s Certified SOC Analyst (CSA) program covers the knowledge required to detect and analyze various types of cyber threats, including XSS attacks. The CSA program’s curriculum includes understanding of IDS logs and the ability to interpret and respond to potential security events indicated by such logs. For further study and verification, please refer to the official EC-Council CSA study guides and course materials.