I've had an usb stick of death for years now. Any system you plug it in instantly freezes. No idea how I made it, but it was certainly not the goal! And whatever I do, I can't get it to overwrite whatever data is on there :P
Oh hey, I had one of those too. I eventually smashed it and threw it out because I tired of plugging it in and having slow down problems.
(I noticed it first when I was working with the jump drive and had the system grind to a halt. Removed the drive and it immediately unfroze. further testing confirmed)