Your phone may start showing full-screen ads even when you aren't using an app.

If you’ve recently discovered a file named in your "Downloads" folder or noticed it attempting to install itself on your Android device, you aren't alone. Mysterious, gibberish-named APKs are a common sight in the world of mobile security—but they are rarely good news.

Go to Settings > Apps and look for anything you don't recognize or that has a blank icon/name. Uninstall it.

If you install OTTMTYvX.apk, you are essentially giving an unknown developer access to your phone. Common risks include: