It might be also possible that your Google account has been compromised which is leading to the problem of random apps keep installing by themselves in the background without your knowledge. As a safe practice, sign out of Google Account on your Android devices and then change the password.

Why are random apps popping up on my phone?

If it’s just now starting to happen, it’s either an app you installed recently or one that auto-updated recently. … As soon as the next ad pops up, go to your home screen and open the Play Store app before opening any other app.

Why do apps get installed automatically?

Unknown apps that automatically gets installed without your knowledge. If you see an app (or apps) on your phone that you have not installed and it has got installed on its own then this too is a sign of malware attack.