That's likely not a malvertisement, it's a web notification that you allowed at some point by selecting allow or yes when the browser asked if you'd accept notifications.
Yes the content may often seem like a malvertisement, and what you received when you were redirected undoubtedly was, but the notifications themselves are a "feature that most browsers added in the last few years and obviously never should have, since they're
regularly abused just like any advertisement system.
The following article discusses these, how they work in the 4 most popular browsers and what can be done to disable them for specific websites or in some cases for all of them.
How to Stop Websites From Asking to Show Notifications
Rob