Download malware bytes, then boot into safe mode. Run malware bytes and it should take care of this all together. I had to do this a few weeks ago on one if my work PC's that I had let the antivirus software outdate. I downloaded Malware bytes and then booted into safe, fixed it all. Then I switched to Avira and it has been good.

I ran malwarebyte in safe mode with networking and it updated then found 3 viruses. None of them said antivirus.net so it could be renamed. If you go back to the link in my earlier post about removing this virus step-by-step it says uncheck one of the server proxy in internet explorer tool before running scans. With that being left uncheck has to do with reason why malware not being active or chances are malwarebyte already removed it and it was just renamed since that website published the tip? I'm able open up files that I couldn't before.

I would go back in and recheck that proxy server setting and then run a full scan rather than a quick one.  It should have taken care of it all, but sometimes they linger and change names.  Take it back to as it was before now that things are working and run it again.  It may be a waste, but it may also find other things.