A keylogger is a piece of software which records keystrokes, unbeknownst to the user. It is a kind of spyware.
Some keyloggers can record URLs of visited websites, emails that have been read or sent, which files have been opened, and even create a video which reproduces all activity on the computer!
Since keyloggers record all keystrokes, they can be used to steal the passwords of the workstation's users. This means that you must be particularly vigilant when you use a publicly accessible computer (like a freely accessible terminal in a place of business, school, or public place like an Internet cafe).
Keyloggers: Software or Hardware
Keyloggers may be either software or hardware. For software, it may be a hidden process (or one with a name that looks a lot like the name of a real system process), which enters the information gathered into a hidden file. Keyloggers can also be hardware, in which case it's a device (cable or dongle) placed in between the computer's keyboard plug and the keyboard.
Protect yourself from keyloggers
The best way to protect yourself from keyloggers is vigilance:
- Do not install software if you're not sure where it came from,
- Be careful when you log into a computer that does not belong to you! On a public computer, before logging on to websites which ask for a password, take a moment to examine its set-up. Check if users have been on the computer before and whether it is possible for less-well-informed users to install software. If there is any doubt, do not log on to secure sites which may cause problems (like online banking services).
If you can, inspect the computer using an anti-spyware
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