Hack an Isolated Computer - No Internet Connection Required

A proof-of-concept idea, which allows a person to send and receive data from a machine that has been kept completely isolated from the internet has been developed by researchers at the Ben Gurion University in Israel. This technique sends information from the machine to a mobile device, specially set up for this activity and later transfers that data to the outside world using normal modes of communications like internet/sms etc.

"With appropriate software, compatible radio signals can be produced by a compromised computer, utilizing the electromagnetic radiation associated with the video display adapter. This combination, of a transmitter with a widely used mobile receiver, creates a potential covert channel that is not being monitored by ordinary security instrumentation," the experts wrote in a paper published on Wednesday.

The attack has four main steps: getting the piece of malware onto the isolated computer, installing malicious code on one or more mobile phones, setting up a command and control (C&C) channel with the infected mobile device, and transmitting signals emanated by the isolated computer back to the attacker.

The malware that's installed on the mobile phone uses the device's FM radio receiver to pick up signals, which have been modulated with sensitive information, sent by the malware on the isolated computer through the monitor's cable. Once the data is sent to the phone, it can be forwarded to the attackers via the Internet or SMS messages.

AirHopper demonstrates how textual and binary data can be exfiltrated from physically a isolated computer to mobile phones at a distance of 1-7 meters, with effective bandwidth of 13-60 Bps (Bytes per second). Enough to steal your secret password.