I know this is a dead thread, but they come up when searching so I wanted to post what helped me in case someone else finds this that needs help.
DMcCoy is right, it is walware, and even if your AV catches it, it will leave an autorun file for not only the c drive but any device plugged in. It even transfered via my home wireless, into devices that were plugged into my other computers, including my Blackberry (or any phone that can transfer files), thumb drives, portable hdd's, memory cards, EVEN into my digital video camera!
To get rid of it plug in all your drives and devices, and scan all drives with Malwarebytes AV, and then run Autorun Eater.
Currently the links to get either software are:
Malwarebytes = Malwarebytes.org
Autorun Eater 2.3 = Autorun Eater software download - CNET Downloads
Hope this helps someone in the future like an old thread did for me!
Good luck!
