Posts Tagged ‘Pret’

PRET is a new tool for printer security testing developed in the scope of a Master’s Thesis at Ruhr University Bochum. It connects to a device via network or USB and exploits the features of a given printer language. Currently PostScript, PJL and PCL are supported which are spoken by most laser printers. This allows cool stuff like capturing or manipulating print jobs, accessing the printer’s file system and memory or even causing physical damage to the device. All attacks are documented in detail in the Hacking Printers Wiki.

The main idea of PRET is to facilitate the communication between the end-user and the printer. Thus, after entering a UNIX-like command, PRET translates it to PostScript, PJL or PCL, sends it to the printer, evaluates the result and translates it back to a user-friendly format. PRET offers a whole bunch of commands useful for printer attacks and fuzzing.


# pip install colorama pysnmp
# pip install win_unicode_console
# apt-get install imagemagick ghostscript
git clone


usage: [-h] [-s] [-q] [-d] [-i file] [-o file] target {ps,pjl,pcl}
positional arguments:
target                printer device or hostname
{ps,pjl,pcl}          printing language to abuse
optional arguments:
-h, --help            show this help message and exit
-s, --safe            verify if language is supported
-q, --quiet           suppress warnings and chit-chat
-d, --debug           enter debug mode (show traffic)
-i file, --load file  load and run commands from file
-o file, --log file   log raw data sent to the target