Don't know what anti-virus you use but first close your browser after downloading CCleaner from
https://www.ccleaner.com/ccleanerdownload and do a full 'Analyze' from the 'Cleaner' tab, do this multiple times until there's just the recurring IE & Windows logs left at the top. Then click on the 'Registry' tab and do a 'Scan for issues' and 'Fix selected issues', you need to do this multiple times until nothing is left.
Download Malwarebytes from
https://www.malwarebytes.com/products/ and when you've ran that download Malwarebytes AdwCleaner (at the bottom of that page) and run it. Then download HitmanPro from
https://www.hitmanpro.com/en-us/hmp.aspx (use the one time option) and run it.
The chances are that you've not actually got anything on your computer and it's 'just' a very dodgy Ad on here but better safe than sorry.