Worm.Autorun is a worm that spreads by altering the autorun.inf file on removable media, such as USB drives, in order to infect every system they are connected to.
This is a generic detection for the Brontok Worm. The Brontok worm has been around since 2005 in one form or another. Most variants have the ability to disable security software and participate in DDOS attacks.
It spreads from system to system by sending out emails and using shared folders.
Malwarebytes can remove this threat without further user interaction.