How does a keylogger assist in computer intrusion?

A keylogger is a type of monitoring software that records the keystrokes made by a user on their keyboard. This functionality plays a significant role in computer intrusion because it allows an attacker to capture sensitive information such as usernames, passwords, credit card numbers, and other personal data without the user's knowledge.

This method of data theft can be particularly effective because it operates silently in the background, making it difficult for users to detect its presence. Once the information is collected, it can be transmitted to the attacker, who can then exploit this sensitive data for various malicious purposes, such as identity theft or unauthorized access to accounts.

The other options do not accurately describe the role of a keylogger in an intrusion context. For example, while a backdoor can facilitate unauthorized access, it does not pertain directly to the action of recording keystrokes. The encryption of data is a protective measure rather than a method of intrusion. Increasing system performance is unrelated to the functions of a keylogger and does not contribute to the process of computer intrusion.