The Android Ad Scam That Strikes After Every Call

Android users are being warned about deceptive apps that display full-screen advertisements whenever a phone call ends. The apps often pose as ordinary tools, including alarm clocks, calendars, cleaners or messaging services, and may be downloaded from the Google Play Store without appearing suspicious.

Researchers have called the scheme “AfterCall” because the ads appear immediately after users hang up. Since the pop-ups are shown outside the responsible app, many people assume their phone or calling service has served the ad, making the real culprit difficult to identify.

How the AfterCall scheme works

The apps rely on Android’s “appear on top” or “display over other apps” permission, which allows content to cover other screens. Because Android treats this as sensitive access, users usually have to enable it manually through the phone’s settings.

Deceptive apps may give misleading reasons for needing the permission. An alarm app might claim it must appear over other apps to work while the phone is locked. A calendar or utility app may refuse to continue unless access is granted.

Once approved, the app monitors the phone’s call status. When it detects that a call has ended, it opens a screen over other apps and displays an advertisement. Some apps also request full-screen notification access, allowing content to appear while the device is locked.

Fig 1. Examples of the pop-up ads (Source DoubleVerify).

Why the apps are difficult to find

The advertisements may appear inside a fake call-information screen containing caller details, a profile image and text designed to resemble a normal Android feature. This makes the ad seem connected to the completed call rather than to an unrelated app.

Some AfterCall apps remove themselves from the Recent Apps list, so checking open applications may reveal nothing unusual. The ads can also promote questionable system cleaner or antivirus tools that claim to fix the problem but may introduce more unwanted software.

How Android users can stop the ads

Users who see pop-ups after calls should review which apps can display over other apps. The exact menu varies, but it is usually found by going to Settings > Apps > Special Access and Appear on Top or Display Over Other Apps.

Look for unfamiliar apps or programs that have no clear reason to cover the screen. A basic notes app, clock, cleaner or calendar would not normally need this access. Disable the permission for anything suspicious and check whether the advertisements stop.

If the app asks for permission again or continues showing ads, uninstall it. Enable Google Play Protect to scan apps for known harmful behaviour. Avoid downloading anything promoted by the pop-ups and think carefully before granting sensitive permissions.