Tracking down the developer of Android adware affecting millions of users

ESET researchers discovered a year-long adware campaign on Google Play and tracked down its operator. The apps involved, installed eight million times, use several tricks for stealth and persistence.

We detected a large adware campaign running for about a year, with the involved apps installed eight million times from Google Play alone.

We identified 42 apps on Google Play as belonging to the campaign, which had been running since July 2018. Of those, 21 were still available at the time of discovery. We reported the apps to the Google security team and they were swiftly removed. However, the apps are still available in third-party app stores. ESET detects this adware, collectively, as Android/AdDisplay.Ashas.

Figure 1. Apps of the Android/AdDisplay.Ashas family reported to Google by ESET

Figure 2. The most popular member of the Android/AdDisplay.Ashas family on Google Play was “Video downloader master” with over five million downloads

Ashas functionality

All the apps provide the functionality they promise, besides working as adware. The adware functionality is the same in all the apps we analyzed. [Note: The analysis of the functionality below describes a single app, but applies to all apps of the Android/AdDisplay.Ashas family.]

Once launched, the app starts to communicate with its C&C server (whose IP address is base64-encoded in the app). It sends “home” key data about the affected device: device type, OS version, language, number of installed apps, free storage space, battery status, whether the device is rooted and Developer mode enabled, and whether Facebook and FB Messenger are installed.