Microsoft doesn't have anything to do with Chromebooks.

I saw it here: http://www.boredpanda.com/programmer-writes-script-against-scammers/

Had to run malwarebytes and Microsoft defender then restored to an earlier date.
It's been gone. It popped up in his email. He didn't open it.

I rebooted it and so far it's ok.

Use CTL-ALT-DEL to bring up the task manager. Then cancel the browser application.

My mother had the same problem with her Chromebook. Rebooting worked for a while, but it did reappear.

If it does come back, try a powerwash. The cool think about Chromebook is that once you sign into your powerwashed computer, all of your settings and shortcuts are there.

How to do a powerwash: https://www.laptopmag.com/articles/how-to-reset-a-chromebook

https://support.google.com/chromebook/answer/183084?hl=en

Be sure to go back and download updates.

Teach1st and Best man23. Good to know this.