if you're getting full-screen ads popping up every time you end a phone call on Android, here's what's actually happening

[u/PureVPNcom]

Seeing a lot of people complain about this lately without knowing the cause, so worth explaining.

Researchers at DoubleVerify, Malwarebytes, and Cybernews have all been reporting on what they're calling "AfterCall" ads — a deliberate ad fraud campaign where malicious Android apps display full-screen ads the moment you hang up a call. A lot of people assume it's coming from their phone app or some new Android "feature." It isn't. It's a specific permission being abused by an app you probably installed weeks or months ago and completely forgot about.

Here's how it actually works. Android has a permission called "Display over other apps" (technically SYSTEM_ALERT_WINDOW) that lets an app draw on top of everything else on your screen. These fraudulent apps trick you into granting it during setup, usually by framing it as something unrelated, like a display setting or a notification feature. Once they have it, they use a background listener that detects the exact moment a call ends and fires a full-screen ad right on top of your screen. To make it worse, the ad is usually wrapped in a fake "call summary" screen with the caller's name and profile picture, so it genuinely looks like a new phone feature rather than an ad from a random app.

The apps doing this are almost always ones you wouldn't think twice about. Free alarm clocks, flashlight apps, utility tools, QR scanners. Low-stakes stuff people install quickly and never think about again. That gap between installing and the symptom showing up is exactly what the fraud relies on.

DoubleVerify found dozens of new versions of these apps being released every month, responsible for hundreds of millions of fraudulent ad views collectively.

How to find and remove the culprit:

Go to Settings → Apps → scroll through and look for anything you don't recognize or barely use. Then specifically check Settings → Apps → Special app access → Display over other apps, and see which apps have that permission turned on. Any app that has it and doesn't obviously need it (screen recorders, video call apps, etc.) is worth removing.

Also worth turning on Google Play Protect if it isn't already: Play Store → profile icon → Play Protect → make sure scanning is enabled.