So how does this work ? Hector Martin gives us a glimpse: Commented reverse engineering assembly: https://twitter.com/marcan42/status/525126731431038977 https:

So how does this work ? Hector Martin gives us a glimpse: Commented reverse engineering assembly: https://twitter.com/marcan42/status/525126731431038977 https://twitter.com/marcan42/status/525126731431038977 So they are rewriting the USB Product ID in EEPROM, only on "fake" chips, hence the Windows USB driver doesn't recognize the device anymore. It should be reprogrammable using the right tools. (https://twitter.com/marcan42/status/525134266112303104 https://twitter.com/marcan42/status/525134266112303104) What allows them to do things differently on different chips: "Figured out the real/clone FTDI difference: EEPROM is written in 32bit units. Even writes are ignored (buffered), odds write both halves." https://twitter.com/marcan42/status/525194603746426881 https://twitter.com/marcan42/status/525194603746426881 And some wisdom: "For those unfamiliar with embedded engineering: most USB (and other) devices can be bricked if maliciously attacked." "Assume ALL devices are brickable by evil code unless proven otherwise. This isn't news. Most devices make no attempt to protect themselves." (https://twitter.com/marcan42/status/525137221431463937 https://twitter.com/marcan42/status/525137221431463937 https://twitter.com/marcan42/status/525137463107272704 https://twitter.com/marcan42/status/525137463107272704)