Showing ads all the sudden on the screen

Ads in android apps are perfectly normal (but are %#*@ annoying) and not necessarily virus related. That is how some (read that as a LOT) of software authors reap income for their free app versions. Telling someone to reset their phone for just a few ads rather than just disabling them or removing them is imho irresponsible. It's simple, don't like the adds don't use the app. Don't like youtube ads, don't use youtube etc etc.

@ahhh I only just noticed that the last comment was written by @mccjong. Not trying to give you a hard time James but things should be checked out before giving advice like doing a factory reset. :-)

FWIW, with respect to "free" virus scanner software I have no problem with any I have used and have never used a paid version of any software that scans for virus or malware. The last time I had a virus was about 20 years ago which was the screen lock type. Of course, using Linux along side my Windows setups eliminate 99% that I was going to be inflicted with any kind of malware or virus (and all the versions of Linux I have used since the 90's have been FREE yes whole various operating systems for absolutely free) The statement "you get what you pay for" is a total myth in my experience (and many others I am sure). BTW I used to repair C64's, Vic 20's and Apple II+ back in the day at the chip component level. Would I buy Apple products today? Nope. Would I buy practically anything else instead of Apple products. Yes. Others mileage might vary on this topic of course. :-)