You need to remember that even the very best of anti-virus software is often unable to handle malware. For that you need to use a dedicated anti-malware program.
If you've
already got the free (or paid) version or Malwarebytes Anti-Malware (MBAM) on your computer, run scan with it to zap the malware which you appear to have.
However I don't recommend downloading the free version now, as it comes with a free trial of the commercial version, which seems to slow some computers to a crawl. So, if you've not already got MBAM, I suggest downloading and running AdwCleaner instead. It's 'out of the same stable' and hence uses the same database of malware, meaning that it should be just as good at doing its job. There's no installation process; you simply run the downloaded file directly:
https://www.malwarebytes.com/adwcleaner/