Cybersecurity researcher from Israel’s Ben Gurion University of the Negev demonstrated a new kind of malware that could be used to covertly steal highly sensitive data from air-gapped systems. The malware can exploit the computer power supply unit (PSU) to play sounds and use it as an out-of-band, secondary speaker with limited capabilities. An attacker can exfiltrate data from audio-gap systems to the nearby phone located 2.5 meters away with a maximal bit rate of 50 bit/sec.
Source: https://thehackernews.com/2020/05/air-gap-malware-power-speaker.html