One of the primary vectors for the distribution of tech support scams is malvertising. You’ll simply be browsing the web when all of a sudden your browser shows a scary page claiming your computer is infected. Behind the scenes, an unscrupulous ad network usually lets a malicious actor push a malicious code snippet instead of a regular advert. Now all you see is a page that looks like a Microsoft website and no matter how many times you try to close the annoying popup, it simply won’t go away.

Over time, various tricks have been used to fool browsers and in particular Google Chrome, which is not surprising considering its market share. Typically we have seen JavaScript code to send what seems to be an infinite number of pop ups, which in reality is a simple loop. Of course there have been variations of this and historically browsers have let users down by not being to handle those tricks cleanly. As of matter of fact, one of the easiest ways to get rid of a browser locker is to kill its process using Task Manager or other such tool.