I can't delete an ad popup

[AC Question]

The popup is from "tracker.tpc.re" keeps popping up continuously. Tried to delete some apps as described here. No luck. Any suggestions?

 

[B. Diddy]

Welcome to Android Central! Keep uninstalling apps until it goes away. Or do a factory reset, then immediately after the Setup Wizard, go to the Play Store and stop any app from installing automatically. Now wait a while and see if the popup comes back. If not, then start reinstalling apps one by one.

If the popup does come back before installing anything, then malware might have installed itself to the system root. This can be hard to get rid of, unless you reinstall the firmware. Which phone is this?