Fansmitter: malware that exfiltrates data from airgapped computers by varying the sound of their fans

In a new paper, researchers from Ben-Gurion University demonstrate a fiendishly clever procedure for getting data off of airgapped computers that have had their speakers removed to prevent acoustic data-transmission: instead of playing sound through the target computer's speakers, they attack its fans, varying their speeds to produce subtle sounds that humans can barely notice, but which nearby devices can pick up through their microphones. (more…)