Autorun infections drop by over one million after Microsoft security update

Microsoft has reduced infection rates for Autorun-related malware by as much as 82 per cent on certain platforms, thanks to a February security update which disabled the feature.

Holly Stewart, of the Microsoft Malware Protection Center, explained in a blog post that the number of infections found by the Malicious Software Removal Tool from January to May 2011 dropped by 82 per cent on Vista SP2, 68 per cent on Vista SP1 and 62 per cent on Windows XP SP3. This amounts to 1.3 million fewer infections on Windows Vista and XP from February to May, she said.

Microsoft also noticed a significant reduction of infection attempts on adjacent systems already protected following the February update. "Some people have wondered why the change to Autorun hasn't reduced infections and infection attempts to zero. The answer is that these families use multiple infection vectors to arrive at a computer," explained Stewart.