One day I found myself having some weird apps in my phone I didn't remember installing. After uninstalling them, they appeared again after after some time.
These apps are:
How did they install themselves and howcome they appear again after uninstalling?
I found out this was most probably caused by SnapPea.
Not only this app installed itself after connecting my phone to my PC (where I did have SnapPea program installed), but also installed those 5 more rubbish apps. If I go to Google Play on the web and look up those self-installed apps, it shows me they are not actually installed. If I open the apps up in Google Play on my phone, it gives me uninstall option, but I can't rate them.
As SnapPea cannot be installed from Google Play, even though it looks quite professional on both phone and PC, the product is certainly a malware.
I strongly recommend uninstalling SnapPea from everywhere.
The most possible cause of this auto download apps is, some trojan virus has affected your smartphone. This virus has gain administrative access to it so that you can not remove it completely. It will auto-download apps and consume your background data again and again.
Try considering following options to prevent auto-download of apps.
I have found solution for this website http://www.theandroidportal.com/prevent-automatic-unwanted-downloads-apps-android/ while searching for this problem. I hope this helps.