The Phantom Keystroker prank gadget is disguised as a harmless circuit board. Once connected to the USB port of your victim’s computer, it will start to randomly pull off some classic Trojan horse stunts.

Simply discreetly attach the Phantom Keystroker to any extra USB port on your victim’s computer, no drivers needed. The Keystroker emulates a keyboard and mouse and periodically makes random mouse movements and types out odd garbage text and phrases. A simple jumper setting allows you to choose between either keyboard garbage typing, annoying mouse movements or both.

An adjustment pot sets the duration between “events”. We recommend you don’t set it too frequently so as to extend the agony. Your hapless co-worker pal will think his computer has been possessed or infected by a destructive virus. As he writhes in anger and furiously dials tech support you can rest easy with a job well done.

The Phantom Keystroker is yours for $24.99 over at ThinkGeek.