Hijacking Printers For Spamming

Having prospered by passing the costs of their operations onto others, spammers have a new way to vex computer users: printer hijacking.

Building on the concept of cross-site scripting, whereby an attacker can inject malicious code in Web pages viewed by others, security researcher Aaron Weaver has demonstrated how an attacker can inject spam messages into a Web site visitor's printer.

Weaver's research is available in a paper published online. It describes how the attack could be initiated by creating a hidden iframe -- a block of code inserted into a Web page and often served from a different domain than the Web page -- and a Web form that submits the spam message to the printer. An attacker could also send the spam message as a fax, if the printer has fax capabilities.

"The end result is that by visiting a Web site on the Internet you could end up sending printer spam to your printer without even knowing that anything happened," Weaver explains in his paper. "Since most printers don't have any security set, it is possible to print anything, control the printer, change the print settings, and even send faxes."

Weaver offers two ways to defend against this attack: Set an administrator password for your printers and consider restricting access to the printer so that it only accepts print jobs from a specific server.