My grandfather has had this message pop up on his phone twice now.

I think it’s fake but want to know what you guys think. His phone screen isn’t cracked it’s just the pop up. It pops up randomly while he’s browsing on his google app. It does say at the top above the link “McAfee Mob…” probably mobile but I couldn’t click it to see the full thing. I’m able to just click the x on the top left corner and it goes away. Whys this happening?