A two-stage attack could allow spies to sneak secrets out of the most sensitive buildings, even when the targeted computer system is not connected to any network, researchers from Ben-Gurion University of the Negev in Israel stated in an academic paper describing the refinement of an existing attack.
The technique, called AirHopper, assumes that an attacker has already compromised the targeted system and desires to occasionally sneak out sensitive or classified data. Known as exfiltration, such occasional communication is difficult to maintain, because government technologists frequently separate the most sensitive systems from the public Internet for security. Known as an air gap, such a defensive measure makes it much more difficult for attackers to compromise systems or communicate with infected systems.
Yet, by using a program to create a radio signal using a computer’s video card—a technique known for more than a decade—and a smartphone capable of receiving FM signals, an attacker could collect data from air-gapped devices, a group of four researchers wrote in a paper presented last week at the IEEE 9th International Conference on Malicious and Unwanted Software (MALCON).