If you thought getting a virus was the worst thing that could happen. When you share USB thumb drive, then think again.
This little beasties, has the ability to totally fry you computer. And it looks identical to a standard USB thumb/flash drive.
Using the 5volt supply found on all USB ports.It acts like a capacitor. Storing up the charge in a few sec. Then releasing it as one pulse of many thousands of volts.
The semiconductors inside microprocessors are used to working on voltages of around 3v. So to be suddenly hit with a few thousand volt pulse. Is all that is needed to destroy them.