Paper-tapping to Exfiltrate Data using Laser Printer
This talk deals with new, innovative, data exfiltration techniques using laser printers. The aim is to understand the possibilities offered by laser printing to insert data subliminally on paper during printing when using office printers. These techniques are similar to those used in auxiliary channel attacks or sidechannel/covert channel attacks), which mainly target confidential environments requiring a high level of security (military, state, industrial sectors). By using the print function, not only it is possible to hide a message (invisible to the public eye) but also to decipher it easily once printed on a paper sheet. The objective is to make people aware of the need of strong security management of printers against unauthorized access to avoid data breach. The main reason lies in the fact that a simple malware hooking the print queue may enable confidential information to be added to legitimate documents and organize the leakage of sensitive information. Demos of our techniques will be made during the talk and source codes will be released.