These trojan downloaders have been plagueing Windows since atleast XP.
My fix:
Safe Mode
run -> msconfig -> startup -> disable all -> apply -> restart in safe mode
This will disable MOST of the startup processes, including most of the fake anti-viruses. These will also disable the exe's for most of your virus protection programs, spyware/malware programs and even ccleaner. You can rename the malwarebytes exe to iexplore.exe. This will allow you to run the program. I have also had success renaming MSE, superantispyware, ccleaner and spybot: search and destroy.
Depending on the speed of the pc, it will take 3 to 5 hours to repair