Apps download automatically, how can I stop this?

[amberskateboard]

apps download automatically pls help

hello! a lot of ads are coming up on my friend's phone and there are a lot of apks being downloaded on the phone, apps we do not know of and are named by numbers, pls help us fix it thank you in advance!

 

[Laura Knotek]

Re: apps download automatically pls help

Are these apps from sources other than Google Play Store?

You can always disable "unknown sources" if you don't want apps from sites other than the Google Play Store.