Security News > 2020 > May > OK, so you've air-gapped that PC. Cut the speakers. Covered the LEDs. Disconnected the monitor. Now, about the data-leaking power supply unit...

Two years ago, for example, he and several other researchers developed a technique dubbed MOSQUITO to exfiltrate data from air-gapped systems using ultrasonic transmissions between speakers.

An obvious defense against acoustic data transmission is to disable any speakers on the protected device, a practice known as audio-gapping.

He and his team have found a way to turn the power supply in an isolated, muted machine into a speaker of sorts, one capable of transmitting data at a rate of 50 bits/sec.

POWER-SUPPLaY alters power consumption by regulating the CPU workload, which causes the switch-mode power supplies in modern electronic devices to alter the switching frequency at which they operate, which is generally between 20 kHz and 20 MHz. Such shifts produce detectable noise in transformers and capacitors.

If your machine is connected to a network, or can transmit data over Bluetooth there are easier ways to exfiltrate data from it.

News URL

https://go.theregister.co.uk/feed/www.theregister.co.uk/2020/05/04/power_supply_attack/