Academics Turn RAM Into Wi-Fi Cards To Steal Data From Air-Gapped Systems

Academics from an Israeli university have published new research today detailing a technique to convert a RAM card into an impromptu wireless emitter and transmit sensitive data from inside a non-networked air-gapped computer that has no Wi-Fi card. From a report: Named AIR-FI, the technique is the work of Mordechai Guri, the head of R&D at the Ben-Gurion University of the Negev, in Israel. Over the last half-decade, Guri has led tens of research projects that investigated stealing data through unconventional methods from air-gapped systems. […] At the core of the AIR-FI technique is the fact that any electronic component generates electromagnetic waves as electric current passes through. Since Wi-Fi signals are radio waves and radio is basically electromagnetic waves, Guri argues that malicious code planted on an air-gapped system by attackers could manipulate the electrical current inside the RAM card in order to generate electromagnetic waves with the frequency consistent with the normal Wi-Fi signal spectrum (2,400 GHz). In his research paper, titled “AIR-FI: Generating Covert WiFi Signals from Air-Gapped Computers,” Guri shows that perfectly timed read-write operations to a computer’s RAM card can make the card’s memory bus emit electromagnetic waves consistent with a weak Wi-Fi signal. This signal can then be picked up by anything with a Wi-Fi antenna in the proximity of an air-gapped system, such as smartphones, laptops, IoT devices, smartwatches, and more. Guri says he tested the technique with different air-gapped computer rigs where the Wi-Fi card was removed and was able to leak data at speeds of up to 100 b/s to devices up to several meters away.