### Comment:
What is a keylogger and how can it be used as a form of malware?

### REPLY:
A keylogger is a software that records all keystrokes made on a computer, including sensitive information like login credentials, credit card details, and personal messages. By installing a keylogger on a target system, an attacker can gain unauthorized access to this information and use it for malicious purposes. For example, they can sell the stolen data on the dark web or use it to compromise the victim's online accounts.