Hardware keylogger
Hardware Keyloggers can be used for Keystroke logging. They plug inbetween a computer keyboard and a computer and log all keyboard activity on an internal memory.
They are designed to work with PS/2 keyboards, and more recently with USB keyboards.
Hardware keyloggers have an advantage over software keyloggers as they begin logging from the moment a computer is turned on (and are therefore able to collect a BIOS password for instance), and do not require software installation (unlike some software solutions).
How do they work?
All hardware keyloggers have to have the following:
- A microcontroller - this interprets the datastream between they keyboard and computer, processes it, and passes it to the non-volatile memory
- A non-volatile memory - this stores the recorded data, even when power is lost
On the whole the recorded data is retrieved by typing a special password into a computer text editor. As the keylogger is plugged in-between the keyboard and computer, it detetects the password has been typed and then starts presenting the computer with "typed" data to produce a menu. Click here for an example tutorial.