This hacktool can be used to activate a pirated version of Microsoft Windows (Windows Vista, Windows 7, Windows 8 and Windows 8.1) and Microsoft Office (Office 2003, Office 2007, Office 2010 and Office 2013).
It is installed as a Key Management Service (KMS) in %SystemDrive% and a front end GUI usually uses this service to automatically activate Windows and Office. An example of the GUI can be seen below.
Analysis by Zhitao Zhou
Alerts from your security software may be the only symptom.