CompTIA CySA+ CS0-003 Exam Questions and Answers PDF

The captured traffic shows TCP packets with the Flags [FPU], which indicate that the FIN, PSH, and URG flags are set. This is characteristic of an Nmap Xmas scan. The Xmas scan is a type of port scan that sends packets with these flags set to determine port states based on responses from the target system. This technique is often used in stealth scanning to evade detection by firewalls or IDS/IPS​.

Nikto's web scan (B) is used for identifying web server vulnerabilities but does not generate TCP packets with such unusual flags​.

Socat's proxying (C) would not exhibit the specific Xmas scan pattern.

Angry IP Scanner (D) is a general-purpose scanner that does not use the TCP flags seen in this capture​.

In case of a phishing attack, it’s crucial to review what actions were taken by the employee and analyze the phishing email to understand its nature and impact.References: CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 6, page 246; CompTIA CySA+ CS0-003 Certification Study Guide, Chapter 6, page 255.

Performing input validation before allowing submission is the best recommendation for remediation of this application vulnerability. Input validation is a technique that checks the data entered by users or attackers against a set of rules or constraints, such as data type, length, format, or range. Input validation can prevent common web application attacks such as SQL injection, cross-site scripting (XSS), or command injection, which exploit the lack of input validation to execute malicious code or commands on the server or the client side. By validating the input before allowing submission, the web application can reject or sanitize any malicious or unexpected input, and protect the user credentials and other sensitive data from being compromised12. References: Input Validation - OWASP, 4 Most Common Application Vulnerabilities and Possible Remediation

D (4: HTTPS traffic to an external IP - 5.29.1.5)

The log entry shows an internal system (172.16.1.30) communicating with an external IP (5.29.1.5) over TCP 443 (HTTPS) using Browser.exe.

HTTPS traffic to an unknown external IP could indicate data exfiltration, as attackers often use encrypted channels to disguise stolen data transfers.

G (7: FTP traffic to an external backup server - bank.backup.com)

The log entry indicates that an internal machine (172.16.1.25) is transferring data to bank.backup.com using FTP (port 21) and FileZilla.

FTP is a major concern because it is an outdated, unencrypted protocol that can be exploited for data exfiltration. If unauthorized, this could be a serious data breach.

Other Options:

A (ARP traffic) → Not a concern (Just address resolution)

B (RPC Kerberos traffic) → Normal for authentication

C (SMB traffic) → Internal file sharing

**E (DNS traffic) → Common, though could be exfiltration in some cases, but not in this log)

F (WUS traffic) → Appears to be Windows Update Service traffic, likely legitimate