"KeyGrabber keylogger is an undetectable keylogger, used for recording keystrokes
on PS/2 and USB keyboards
A hardware keylogger is a tiny electronic device capable of capturing keystrokes
from a PS/2 or USB keyboard. A keylogger contains advanced electronic circuitry for
monitoring a keyboard's USB or PS/2 connection, filtering keystroke data,
and recording the data to internal memory.
The built-in memory typically has several megabytes (or even gigabytes),
meaning it can hold years-worth of typing."