Using the microphones and speakers that come standard in many of today’s laptop computers and mobile devices, hackers can secretly transmit and receive data using high-frequency audio signals that are mostly inaudible to human ears, a new study shows.
Michael Hanspach and Michael Goetz, researchers at Germany’s Fraunhofer Institute for Communication, Information Processing, and Ergonomics, recently performed a proof-of-concept experiment that showed that “covert acoustical networking,” a technique which had been hypothesized but considered improbable by most experts, is indeed possible.
Their findings, detailed in a recent issue of the Journal of Communications, could have major implications for electronic security. ”If you have a high demand for information security and assurance, you would need to prepare countermeasures,” Hanspach wrote in an email to Inside Science. In particular, it means “air-gapped” computers — that is, computers that are not connected to the Internet — are vulnerable to malicious software designed to steal or corrupt data.