Popups

Hi
Hoping this is the right part of the forum to ask, apologies if not.
I’ve suddenly started getting loads of popups with virus notifications, or with links to porn sites. I’m assuming this is some sort of adware so I haven’t clicked on any of them. I downloaded the paid version of Avast thinking it would help, but it’s making no difference. Doesn’t Avast work for this kind of thing? Or am I missing something obvious/doing something wrong?
Any help would be much appreciated, the popups are extremely irritating and I’d like them gone, especially as I teach and often have to share my screen with students.
Thanks.

Run a scan with Malwarebytes Antimalware free and Malwarebytes Adwcleaner and let them remove what they find

https://www.malwarebytes.com/
https://www.malwarebytes.com/adwcleaner/

also see info in step #1 here https://forum.avast.com/index.php?topic=194892.0

you may attach scan logs here