Your problem may well be a rootkit as that tends to be the symptom “The text I get from avast says its URL:Mal and in svchost.exe.”
I don’t know if OTS would find this or not and I’m not very familiar with OTS, so it would need someone else to analyse the log.
In the meantime you can run this tool which is specifically looking for one type of rootkit MBR Master Boot Record rootkit.