I hadn’t realized they’re more than just memory:

“People look at these things and see them as nothing more than storage devices,” says Caudill. “They don’t realize there’s a reprogrammable computer in their hands.”

In an earlier interview with WIRED ahead of his Black Hat talk, Berlin-based Nohl had said that he wouldn’t release the exploit code he’d developed because he considered the BadUSB vulnerability practically unpatchable. (He did, however, offer a proof-of-concept for Android devices.) To prevent USB devices’ firmware from being rewritten, their security architecture would need to be fundamentally redesigned, he argued, so that no code could be changed on the device without the unforgeable signature of the manufacturer. But he warned that even if that code-signing measure were put in place today, it could take 10 years or more to iron out the USB standard’s bugs and pull existing vulnerable devices out of circulation. “It’s unfixable for the most part,” Nohl said at the time. “But before even starting this arms race, USB sticks have to attempt security.”

Caudill says that by publishing their code, he and Wilson are hoping to start that security process. But even they hesitate to release every possible attack against USB devices. They’re working on another exploit that would invisibly inject malware into files as they are copied from a USB device to a computer. By hiding another USB-infecting function in that malware, Caudill says it would be possible to quickly spread the malicious code from any USB stick that’s connected to a PC and back to any new USB plugged into the infected computer. That two-way infection trick could potentially enable a USB-carried malware epidemic. Caudill considers that attack so dangerous that even he and Wilson are still debating whether to release it.

Great.