Bridgeware: a class of malware that allow attackers to overcome ('bridge') the air-gap isolation

https:// cyber.bgu.ac.il/advanced-cyber/airgap

https:// arxiv.org/pdf/1804.04014.pdf

Tracking using Ultrasound/Ultrasonic signals

http:// ubeacsec.org/

https:// www.wired.com/2016/11/block-ultrasonic-signals-didnt-know-tracking/