Non-repudiation ensures that a message sender cannot deny the authenticity of their sent message. This is crucial in banking communications for legal and security reasons.
The goal of allowing a message recipient to prove the message's origin is non-repudiation. This ensures that the sender cannot deny the authenticity of their message. Non-repudiation is a fundamental aspect of secure messaging systems, especially in banking and financial communications.

Regular expressions are powerful tools for searching text based on specific patterns, making them ideal for parsing Linux log files to detect security events with repeatable patterns. In Bash, regular expressions can be used in commands like grep or awk to efficiently filter log data. CompTIA CySA+ emphasizes the use of regular expressions in log analysis for pattern matching, a common requirement for identifying suspicious activities in log files. Options B, C, and D are less suited for this specific task due to their limited pattern- matching capabilities or platform constraints.

Port 3389 is commonly used by Remote Desktop Protocol (RDP), which is a service that allows remote access to a system. A vulnerability on this port could allow an attacker to compromise the web server or use it as a pivot point to access other systems. However, if the firewall blocks this port, the risk of exploitation is reduced.
References: CompTIA CySA+ CS0-003 Certification Study Guide, Chapter 2: Software and Systems Security, page 67; CompTIA CySA+ Study Guide: Exam CS0-003, 3rd Edition, Chapter 3: Software and Systems Security, page 103.