Essexboy,
I ran Combofix as instructed. Log attached. The issue persists: I continue to receive pop-ups like the one previously described.
One hiccup: I physically disconnected my computer from the internet before disabling avast! (as I'm concerned about whatever information the virus is trying to transmit), I then ran ComboFix, but it obviously wasn't able to update to the latest version. Per your instructions, I did not re-run ComboFix. Should I update it and re-run?
Many thanks.