What is keylogger?

Keylogger (aka keylogging software or keylogging device) is a tiny computer program or small device installed in a computer that is designed to hijack keystrokes that a user type on their keyboard.

Keylogging devices require physical access to a given computer so that they can be mounted by the hacker, whereas software keyloggers require installation of an infected software.

Some keyloggers are genuine computer programs that are used to control a PC's usage (e.g. parental control software such as SpectorPro), whereas the majority of keystroke loggers are malware whose sole purpose is to hijack confidential information such as logins and passwords.