Computers separated from the internet are vulnerable to new hacks using unconnected smartphones to steal data such as passwords and keystrokes, according to Israeli researcher Mordechai Guri.
Air-gapped computers do not have wireless activity and are used by governments to store classified information and by organizations to manage critical infrastructure such as power and energy systems.
These machines are not impenetrable, however, and Mr. Guri disclosed a new method that uses malicious software to create ultrasonic frequencies on the secure machines that are detectable by smartphones located nearby. Information from the computer is transmitted through the frequency that is collected by the phone and deciphered by a cyberattacker.