Hardware keylogger (keystroke recording devices, hardware keyloggers, etc.) are small device that can be attached somewhere between the keyboard and the computer or built into the keyboard. They record all keystrokes. The process is absolutely invisible for the user.

Hardware keyloggers do not require any software to be installed on the computer they are tracking in order to successfully intercept all keystrokes. Anyone can secretly connect such a device to a PC - a colleague, an cleaner, a visitor, etc. It does not matter if the computer is on or off at the moment when a hardware keylogger is being attached.

After that the intruder can take the device off at any convenient moment and download its contents (recorded keystrokes) whenever convenient as well. The amount of the internal nonvolatile memory in these devices allows them to record up to 10 million keystrokes. It is really easy to attach such a device to a computer. Their appearance vary so much that even a specialist is not always able to detect one when he is doing information audit.

KeyKatcher, KeyGhost, MicroGuard, Hardware keylogger hardware keyloggers manufactured by Alien Concepts, Inc., Amecisco, KeyGhost, Ltd., MicroSpy, Ltd., Inc are especially known on the market.

Hardware keyloggers are divided into internal and external. Their peculiarities are described below.

External hardware keyloggers.

External hardware keyloggers are attached between a usual PC keyboard and a computer and record each keystroke. They need neither batteries, no software and they can work on any PC. You can attach them to one computer to record information and then to another computer to look through it. Modern hardware keyloggers are devices that look like some equipment for a PC.

Internal hardware keyloggers.

An external hardware keylogger that has its hardware intercepting module built into the keyboard is most difficult to detect.

It is a small built-in device attached to a cut in the keyboard cord and covered by some insulating material.