Security News > 2020 > May > Power Supply Can Turn Into Speaker for Data Exfiltration Over Air Gap
A researcher has demonstrated that threat actors could exfiltrate data from an air-gapped device over an acoustic channel even if the targeted machine does not have any speakers, by abusing the power supply.
Researcher Mordechai Guri from the Cyber-Security Research Center at the Ben-Gurion University of the Negev in Israel has shown that a piece of malware can cause a device's power supply unit to generate sounds that can be picked up by a nearby receiver.
The attack involves starting and stopping the CPU workload, which influences the switching frequency of the power supply, which in turn impacts the transformers and capacitors in the power supply.
The researcher demonstrated that a power supply can play the song "Happy Birthday" using this method.
Over the past years, they showed techniques for silently stealing data using fan vibrations, heat emissions, hard drive LEDs, infrared cameras, magnetic fields, power lines, router LEDs, scanners, screen brightness, USB devices, and noise from hard drives and fans.