1. A program that runs in the background that records all the keystrokes. Key point: Once keystrokes are logged, they are shipped raw to the hacker. The hacker then peruses them carefully in the hopes of either finding passwords, or possibly other useful information that could be used to compromise the system or be used in a social engineering attack. For example, a key logger will reveal the contents of all e-mail composed by the user. Key point: Keylog programs are commonly included in rootkits and remote administration trojans. Key point: You can also purchase hardware devices that plug-in between the keyboard and the main system (for PCs). These are OS independent, they simply start recording, then the hacker can retrieve the device and instruct it to simply spit out all the characters back again on the hackers system. History: In November of 2001, the FBI revealed it has developed a keylogger Trojan as part of its Carnivore surveillance technologies. From Hacking-Lexicon