Browser infected Pop-up
First - as you  are probably aware now.  You NEVER click on a link from an unknown source. I repeat - NEVER. Next time, just close the window without clicking on any links Second - if you can't figure out which malware app was installed , you need to consider doing a factory reset on your phone to eliminate all threats.   A factory reset will erase the data (Text messages, photos, videos, settings, everything on your phone will be removed in the reset process.).... I would do it anyway just to be certain that I got it all.  You may be able to backup any pictures or video.  The easy way to reset is to go to Settings -> backup and recovery -> Reset Device -> Erase everything.