Standard computer hardware has been hacked by a team of security researchers to send information out of an office through sound waves.
The program built by Red Balloon Security is able to take control of the physical prongs on general-purpose input/output circuits and vibrates them at specific frequencies set by the controller to transmit data from the computer.
The sound need not be audible and the signal can be picked up with an AM radio antenna a short distance away. The so-called 'Funtenna' would be hard to detect because no traffic logs would catch data leaving the premises.
Red Balloon's lead researcher Ang Cui demonstrated the system for reporters ahead of his talk later today at the annual cyber-security conference Black Hat in Las Vegas. He said he would release 'proof-of-concept' code after his talk today so that other researchers could verify his work.
While the technique may pique the interest of spy agencies, who have long sought covert ways of extracting data from computers, Cui said, hackers would need an antenna close to the targeted building to pick up the sound waves.
They would need to find some way to get inside a targeted machine and convert the desired data into a format that could be transmitted by the antenna.