Thanks for the link. This was one of the first things I thought of because in the past when my virus protection did not catch something, Malewarebytes standalone malware scanner did the trick. I went to there website and could not find this and the company wanted me to install their virus software. I ran the scanner in your link and it and it found:
PUP.Optional.Legacy - 1 item found
PUP.Optional.RegistryCleaner - 1 item found
PUP.Optional.WebCompanion - 4 items found
And I quarantined them all. I hope that did the trick. I leave on a 3 week vaction tomorrow to various parts of Southeast Asia so I'll have to followup when I get back, but I just found out how to duplcate the error and I I think it may be various websites that are being infefected. Right now it appears to be happening on the MediaBiasFatcheck site. I went there using this link, just wanted some info about Human Events:
https://mediabiasfactcheck.com/human-events/#google_vignetteIn order for the malicious pop-up to appear, you have to leave the tab open a while and be looking at other tabs and after (sometimes long) a time, go back to that tab and you might see the popup sitting there, it blurs out the page you are on so you can only see the ad. I made a screenshot of the malicious link:
https://imgur.com/a/thG1cV9The popups "always" look similar, ie a white box with the word "ad" at the top right, very generic looking, and looks like it might be an ad for a legitimate website, in this case Viator. and the only options are Open or Close. I once clicked Open and had the experience I noted above.
If I were not very busy and getting ready for my vacation, I'd click OPEN and see of the ransomware page popped up again successfully highjacking some of the functions of my computer like my disappearing task bar, failure of ctrl-alt-del to work etc as noted above, I just don't have the time right now to continue playing with it.
Maybe it was one of those things Malwarebytesfound.