Should you be able to brick a keyboard just by writing a driver to flash the lights on it? We don’t think so either. [TheNotary] got quite the shock when embarking on a seemingly straightforward project to learn C++ on the x86-64 architecture with Windows and sent it straight to Silicon Heaven with only a few seemingly innocent USB packets.
The project was a custom driver for the XVX S-K80 mechanical keyboard, aiming to flash LED patterns across the key LEDs and perhaps send custom images to the integrated LCD. When doing this sort of work, the first thing you need is the documentation of the communications protocols. Obviously, this was not an option with a closed-source project, so the next best thing is to spy on the existing Windows drivers and see how they worked. Using Wireshark to monitor the USB traffic whilst twiddling with the colour settings, it was clear that communications were purely over HID messages, simplifying subsequent analysis. Next, they used x32dbg (now x64dbg, but whatever) to attach to the existing driver process and trap a few interesting Windows system calls. After reading around the Windows API, a few candidate functions were identified and trapped. This gave them enough information to begin writing code to reproduce this behaviour. Then things got a bit odd.
Continue reading “Reverse Engineering A Keyboard Driver Uncovers A Self-Destruct Code”
