keysniffer

A Linux kernel module to grab keys pressed in the keyboard, or a keylogger.

keysniffer was initially written with the US keyboard (and conforming laptops) in mind. By default it shows human-readable strings for the keys pressed. However, as keyboards evolved, more keys got added. So the module now supports a module parameter codes which shows the keycode shift_mask pair in hex (codes=1) or decimal (codes=2). You can lookup the keycodes in /usr/include/linux/input-event-codes.h.

The keypress logs are recorded in debugfs as long as the module is loaded. Only root or sudoers can read the log. The module name has been camouflaged to blend-in with other kernel modules.

You can, however, execute a script at shutdown or reboot (the procedure would be distro-specific) to save the keys to a file.

DISCLAIMER: keysniffer is intended to track your own devices and NOT to trespass on others. The author has never used it to compromise any third-party device and is not responsible for any