A keylogger is a program that records the keystrokes on a computer. It does this by monitoring a user's input and keeping a log of all keys that are pressed. The log may saved to a file or even sent to another machine over a network or the Internet.
Keylogger programs are often deemed spyware because they usually run without the user knowing it. They can be maliciously installed by hackers to spy on what a user is typing. By examining the keylog data, it may be possible to find private information such as a username and password combination. Therefore, keyloggers can be a significant security risk if they are unknowingly installed on a computer.
The best way to protect yourself from keylogger programs is to install anti-virus or security software that warns you when any new programs are being installed. You should also make sure no unauthorized people have access to your computer. This is especially true in work environments. You can also periodically check the current processes running on your computer to make sure no keyloggers or other malware programs are active. While it is unlikely that you have a keylogger programs installed on your computer, it is definitely worth it to check.