Ok, combofix round two here we go
Also, I was just thinking (after getting another couple of pop-ups following this last round of combo fix, one from avast.setup and one from svchost.exe both Url:Mal) would it be worth reinstalling avast? Or is the problem definitely not with avast? It's just that, for example, the malwarebytes protection module is running now on my system and doesn't pick up these supposed malicious url connections, just avast...
EDIT: came back to my computer and the avast screensaver scan just found OTL.exe to be a threat of type malware-gen, but I downloaded it from your link so am I safe to "do nothing" with it?