Number of Autorun-related malware infections dropped 59 percent on XP machines and 74 percent on Vista. Figure is equivalent to a 1.3 million drop compared to the levels seen in 2010. The transformation appears to date from the retrofitting in January of this year of security that allowed the AutOrun feature to be turned off on Windows XP and Vista for risky media such as USB sticks but not for others such as C Ds and DVDs. Microsoft has tracked Taterf, Rimecud, and a large generic category of unknowns labelled simply ‘Autorun'”]
Source: https://www.csoonline.com/article/2128782/autorun-malware-being-routed–says-microsoft.html