[AC Question]

My Samsung Galaxy s5 has gotten a virus. It drains my battery really fast and I get these pop-up ads. I don't know what to do. I've tried to download 360security which it advised, but it didn't do anything. Please help.

[Crashdamage]

First, uninstall 360 Security. It's terrible and throws up pop-up ads like you're trying to get rid of. To get rid of it uninstall like this:
Settings > Apps > All > 360 Security > Force stop > Clear cache > Clear data >Uninstall Reboot the phone.

Next, uninstall ALL task killers, RAM memory optimizers/boosters, battery savers/repairers, cache cleaners, antivirus, etc etc. None of that stuff is necessary. Such apps are actually counterproductive and some are just plain evil. Many of them are guilty of pop-up nags and far worse. They actually waste power and disrupt critical system processes and degrade performance. Not to mention the nag ads many throw up. When done, reboot the phone.

Uninstalling crapware may solve the pop-up problem. If not, try clearing app caches the correct way:
Settings > Storage > tap Cached data > OK. Reboot the phone.
Note: While clearing caches doesn't really hurt anything, cache files are there for a purpose and should be left alone unless you have a problem that might be related to them.

If you still have pop-ups try installing Malwarebytes. It is not an antivirus progam in the usual sense.
https://play.google.com/store/apps/d...imalware&hl=en

If you STILL have pop-ups, the next step is clearing the cache partition. The exact procedure for that varies by device.
Next step after clearing the cache partition would be a factory reset.