That was my first thought but if it was there is must have been under a ficticius title. The final resolution was Buying and using MalwareRemovalBot. RegVac did not get it but I am wondering if another of your programs would have taken care of it.
I was thinking of Windows Defender and not Windows PC Defender. Windows PC Defender is a program that claims to be an antivirus program but actually puts viruses on your computer. You can do a search online for Windows PC Defender and find removal instructions for it. Here is one page I found - http://www.2-spyware.com/remove-windows-pc-defender.html. None of our programs deal with viruses and so none would take care of it.