Keystroke loggers are small tools which covertly capture the user's keystrokes on his/her computer. They record every click the user makes including typos, backspacing and retyping. Some loggers will also capture the user's mouse movements and clicks and may even take snapshots of the contents of the user's computer screen.
Keystroke loggers were first developed by researchers to see how users interact with new software and to identify sources of error. More commonly, keystroke loggers are used by hackers as a means to obtain passwords or encryption keys and to bypass the user's security. Because the keystroke logger captures the information at the point of keyboard clicking, it can capture information which would normally be hidden from display.
Keystroke loggers are widely available on the internet.
Hardware keyloggers come in two types – visible (a device that attaches to the keyboard cable) and invisible (installed by opening up the keyboard case and soldering the logger into the circuits). A hardware logger will store the information until the person who installed it comes back to collect and download the data.
A software logger can be installed on your machine by a virus, worm or trojan horse. Software loggers will typically attempt to send the data back to the hacker through the internet. Because they are so easy to spread to a victim's computer, software loggers are now more common.
- Always keep your antivirus program and firewall turned on and up-to-date. Run anti-spyware software regularly.
- When using public computers (such as the library or a cyber-café), avoid visiting sites that require you to enter login details.
- Use common sense.