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.
Malwarebytes can remove Worm.AutoRun.FLDGen without further user interaction, but you may want to format any affected drives before using them again. Be careful with the executable files that you decide to keep as they could be the “infector”.
Microsoft has set AutoRun to “off” by default to mitigate the impact of this worm. So be warned if you change that setting. Also, AutoPlay is a similar feature that can be abused more or less in the same way.