What is this alarming popup I'm getting and why isn't Avast catching and stopping it?

This popup is why I signed up for Avast Premium. This window popped up a few times, most of the times I just closed it, but one time I made the mistake of clicking “close this page” on it and it locked up my computer screen and made it look like it was opening a dozen pop-us with a voice saying “your computer has been compromised, please contact Windows Support” and a phone number that was not Windows Support. Fortunately, I have a second monitor that they didn’t cover up, and I was able to open up the task manager and identify their process to kill it. But I worried what they had managed to get into my system somehow, so I ran a smart scan and signed up for Avast premium right then and there, and then ran another smart scan, both of which came up clean.

However, today, this same pop up popped up again. So the purpose that I got Avast premium to stop still persists. Any idea what it is and any idea why Avast is worthless to stop it?

Im no expert as never seen that before on yahoo. first question do you have a yahoo account or yahoo email.

When this first happened did you log out of yahoo and immediately change your password?

enter your email here to see if its shown up on a list on the dark web Has Your Email Been Hacked? Free Data Leak Check | Avast

Hopefully someone else may be able to advise further.

I don’t have a Yahoo account that I know of. Everything you see on screen is fake. It’s not a browser window. It doesn’t go to the URL is says. And if you click anything but the X-button you authorize it to attack.

Thats worrying then. I would do a boot time scan to see if it can be caught before everything else loads and also download malwarebytes https://www.malwarebytes.com/ and run a scan with that.

Are you on windows 10 or 11 and is that IP address actually yours?

worth checking where your default browser startup page is set too. mine opens with duckduckgo but i have years ago once it got changed somehow to yahoo by default but luckily there was no dodgy popups.

I only know how to do this using firefox as i wont use any other browser. top right of page either 3 dots or 3 lines then go to settings. then check both images below and make sure yahoo is not set in either boxes.

This is just guesswork as i have no clue what it is but if it locks you screen then its either a scam but then that would not normally lock up your pc or a virus/trojan or some sort of malware or even ransomware.

I am wondering if it is a scam.
I suggest you clear your browser cache and disable browser add-ons. Check if any browser add-ons or extensions have been added that you do not recognise and remove them.

Check that alert url at

Note: I am not an Avast team member, just another user.

I at first thought that but ive not heard of scams actually lock the screen with multiple popups and a voice saying you have been compromised