Microsoft has disabled the AutoRun feature of Windows Vista and Windows XP in the Patch Tuesday updates.
AutoRun is a feature that allows automatic execution of programs or operating system actions based on inserting new media such as CDs, DVD and USB drives. The feature has long been a favorite target of malware authors, facilitating the spread of worms via physical media.
In a post on the Windows Malware Protection Center blog, Microsoft researcher Holly Stewart identified the most common Windows worms, noting that "all of these worms share is a common propagation method. They all abuse the autoplay feature of Autorun."
"Windows XP users were nearly 10 times as likely to get infected by one of these worms in comparison to Windows 7," said Stewart, suggesting that Autorun behavior of older operating systems was at least partially to blame.