New USB malware that steals data – USB Thief

Source: http://www.scmagazine.com/new-usb-based-data-stealing-malware-detected-in-wild/article/485140/

Win32/PSW.Stealer.NAI aka USB Thief is a data stealing type malware that is hard to detect and leaves no trace behind.
The malware is used to steal data off networks and uses encryption. This could be a tool intended for targeted use.