Keylogger

A keylogger is a computer program that captures the keystrokes of a computer user and stores them. Modern keyloggers can store additional information, such as images of the user’s screen. Most malicious keyloggers send this data to a third party remotely (such as via email).

Keyloggers are also highly useful for law enforcement and espionage – for instance, providing a means to obtain passwords or encryption keys and thus bypassing other security measures.

Keyloggers come in both hardware and software variants. A hardware keylogger is plugged into the keyboard, between the keyboard and the computer. It records keystrokes onto the device, and the log is retrievable from typing a password into notepad where the device shows all the keys that have been typed. The advantage of a hardware keylogger is that it cannot be detected by software, unlike software keyloggers.