I had a customer that sustained this. It was a persistent one. To disinfect it required boot scans with Spybot S&D. Ordinary scans in session context would not remove it.--Scott Brown Consulting
Sorry, don't understand "boot scans". I have spybot and use it but it's not getting it.
Go into Advanced mode, then do Settings > "System start" > "Run program once at next system startup"