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LaserShark: Fast, Bidirectional Communication into Air-Gapped Systems
- _Microft 5y ago"LaserShark: Establishing Fast, Bidirectional Communication into Air-Gapped Systems", doi:10.1145/3485832.3485911 Available at: https://intellisec.de/pubs/2021-acsac.pdf https://intellisec.de/pubs/2021-acsac.pdf
- zw123456 5y agoTL;DR The whole idea completely depends on the LED on the target computer is driven directly by a GPIO pin of a CPU you can hack and reverse the direction of the GPIO pin to somehow be an input rather than output. Also, that said LED is driven directly by the GPIO pin and not via a driver transistor. The idea of turning an LED on and off really fast to send a message out is not new, that has been done a long time ago. Here they are suggesting that an LED can be driven as a light sensor with a high enough power laser, which can then induce a high enough voltage on the LED to reach the trigger voltage of the GPIO. It all sounds interesting, but there are a lot of ifs there. I guess it can work in very specific cases where you had access to the low level firmware of a MCU and that the LED was driven by a GPIO pin that can be re-programmed to be an input pin and the LED is connected to it by at most a resistor. The other if is that you would need to be able to hit it with a laser so that means someone would have to leave the device visible through a window or something, which seems sort of unlikely since the idea of air gap is to avoid any contact with the outside world. But I guess the lesson here is if you are air gapping something don't put it near a window. But that is sort of common sense anyhow.