If you thought stealing data via fan vibrations was nefarious, wait till you read about this method using graphics cards. Researchers at security firm Duo managed to turn an AMD Radeon Pro WX3100 graphics card into a radio transmitter.
The idea behind this is using the GPU-generated radio frequencies when it’s working at different clock rates. Potential hackers can gain control of this from the graphics card settings. In this case, from the Radeon Pro power controls. The resulting radio waves can be picked up through a wall, and up to about 15m away.
We turned a Radeon GPU's shader clock in to a tunable radio transmitter that can jump through walls & get picked up 50ft away.
— Mikhail Davidov (@sirus) April 22, 2020
As crazy as this method sounds, there’s a lot of work going into preparation for this to work. To start, a potential hacker will have to first develop an encoding technique for the data transmission.
Then there’s the matter of accessing power settings for the graphics cards remotely. This will need a prior infection of the target machine with malware. Which can be difficult to achieve on an air-gapped machine (not connected to the internet or inseure networks), the whole point of the convoluted attack method.
The other part of the attack is getting a radio receiver to get the transmitted data from the manipulated GPU. For this, the researchers used a Software Defined Radio device, combined with a UHF and directional ultra-wideband antenna. The researchers also used open source software for the receiver.
Considering the nature of the attack, it’s possible for this to work on Nvidia-made GPUs, or even CPUs and other clock-driven devices. But because it’s such a convoluted way of doing things, you likely won’t have to worry about this being used on you. Unless, of course, you have some national secrets stored in your PC and your neighbour knows about it.