Samsung Galaxy S6 — Factory reset won't fix this malware

I installed an .apk app it has ads as you are leaving. Tolerable, but it put pop ups on my other apps and after uninstalling it left them on my phone. It also added an extra lock screen with ads. My phone keeps refreshing, so if I'm texting I get part way through and it refreshes and I have reselect the person and start again or if I'm lucky from the draft. I did a factory reset same problem. I went into safe mode and reset from there. Same problem. It seems to be trying to install something [lock screen maybe even if i didnt remove it yet], and gets stuck in the install wizard on my phone. It gets to refresh several times a minute.My phone is very hot and doesn't fully recharge even over night. I have a galaxy 6s. I have eset virus scam and malwarebytes found nothing wrong. Please help