Israeli scientists have found a way through which hackers can steal sensitive data from the highly secured computer just by tapping into the vibrations from a cooling system fan.
Hackers can encode data into fan vibrations that could be transmitted to a smartphone placed in the vicinity of the targeted computer.
Lead cyber-security researcher Mordechai Guri at the Ben-Gurion University of the Negev said, “We observe that computers vibrate at a frequency correlated to the rotation speed of their internal fans. Malware can control computer vibrations by manipulating internal fan speeds. These inaudible vibrations affect the entire structure on which the computer is placed.”
“The covertly transmitted vibrations can be picked up by a smartphone resting on the same surface as the computer.”
“Since accelerometer sensors in smartphones are unsecured, they can be accessed by any app without requiring user permissions, which make this attack highly evasive.”
Guri devised the procedure, named AiR-ViBeR, with an air-gapped computer setup. Air-gapped computer systems are isolated from unsecured networks and the internet as a security measure.
Scientists reported, “Three measures would help secure a computer system against such an assault. One would be to run the CPU continuously at maximum power consumption mode, which would keep it from adjusting consumption. Another would be to set fan speeds for both CPU and GPU at a single, fixed rate. The third solution would be to restrict CPUs to single clock speed.”
Guri said of AiR-ViBer, “This is the very essence of a side-channel attack. The malware in question doesn’t exfiltrate data by cracking encryption standards or breaking through a network firewall; instead, it encodes data in vibrations and transmits it to the accelerometer of a smartphone.”
AiR-ViBer relied on vibration variances sensed by an accelerometer capable of detecting motion with a resolution of 0.0023956299 meters per square second. There are other means of capturing data through side channels. They include electromagnetic, magnetic, acoustic, optical, and thermal.
- AiR-ViBeR: Exfiltrating Data from Air-Gapped Computers via Covert Surface ViBrAtIoNs. arXiv:2004.06195