Cleaning up a customer's PC, I made the mistake of leaving a tab open on Yahoo's home page. Only 1 minute later: malvertized. Sunuva...
I did it again to pin down the cause, & indeed it's Yahoo's ads breaking out, taking over the page, & loading scary messages that make it difficult to leave.
I can't stress enough, folks, that an ad blocker is Internet SECURITY software.
For anti-adblock pop-ups, I usually recommend the more extreme action of blocking JavaScript on that website, either through "Site Settings" behind the info icon in the Chrome address bar, or through an extension such as NoScript for Firefox & ScriptSafe for Chrome/Chromium.
If the page content is completely inaccessible with both ads & JS blocked, then there's nothing for it; I recommend abandoning the site. Like a game of Three-Card Monte in an alley, the only winning move is not to play.
Unlike the simple on-off switch built into some browsers, NoScript & ScriptSafe are selective & granular JavaScript blockers. That means, with either of them, you can allow JavaScript from a website's domains while blocking & distrusting JavaScript from ad network domains. And that distrust of an ad network's JavaScript (or any domain's JS) follows you across the World Wide Web to every website attempting to use it on you, not just the one site you distrusted it on.