Please launch Windows Scheduler and delete the following task and reboot the machine:
Microsoft\Windows\eFECya
Should the problem persist, delete the following registry value and reboot the machine:
HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tasks\{D24444D6-714D-4331-AC2B-CE934A3A0CAE}
I'd also recommend enabling detection of potentially unsafe applications as well as the LiveGrid Feedback system for maximum protection.
jasonphilip gave kudos to Marcos in powershell/psw.coinstealer.b
