If you run Smitfraudfix first you will never get a message from Combofix that you have a script running and shuts Combofix down, that is the virus stopping it.
I found if you run Smitfraudfix, Combofix and Malwarebytes in Safemode with networking, in that order you will be fine and yes the terrible three will murder the viruses on the machine. If Smitfraudfix and Combofix want to update in safemode, let them. I also install, update and run Malwarebytes in safemode with networking.
This sequence works great for me and I thought I would pass on my good experiences to everyone.