Ariad is a tool to prevent inserted USB sticks from executing code. Technically, it achieves this goal with a minifilter driver by blocking access to \autorun.inf on USB sticks. When you try to access autorun.inf on USB sticks, you’ll get an access denied error. Hence the name Ariad (AutoRun.Inf Access Denied).
http://blog.didierstevens.com/programs/ariad/
