Microsoft Windows does not properly warn the user before enabling additional Human Interface Device (HID) functionality over USB, which allows user-assisted attackers to execute arbitrary programs via crafted USB data, as demonstrated by keyboard and mouse data sent by malware on a smartphone that the user connected to the computer.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A12566
http://www.cs.gmu.edu/~astavrou/publications.html
http://www.blackhat.com/html/bh-dc-11/bh-dc-11-briefings.html#Stavrou