Since that's no virus I think you should start uninstalling apps or just reset the phone like I do. I don't keep things on my phone.
Beginning yesterday, 7.7.16, a popup called ninaxu is coming up on my phone urging me to go repair my device; it says I have 13 viruses and that it is from looking up porn. It gives me 2 minutes to act before my phone will be destroyed. Now, obviously this is all false, but it locks up my phone and I often have to reboot it. I have searched for info,and only 2 sites come up amd I do not know if I can trust them. This has happened about 6 times in the last 24 hours. I could be looking at a webpage, reading an article, or nothing when it pops up. I want this gone,and no virus program is working. Can you help?