These advertisements are displayed in the lower right corner of the screen urges users to play online games, visit suspicious web pages, install web-browser add-ons & so on.
Scammers abuse ‘push notifications’ to avoid antivirus and ad blocking software by displaying intrusive ads. Push notifications are originally designed to alert users of newly published news.
pop ups are a social engineering attack which uses the browser notification feature to trick unsuspecting users into accepting push notifications via the browser.