Dubbed Necro, the app was infected with code that caused 100 million infected devices to connect to attacker-controlled servers and download secret payloads.
Now, the same Kaspersky team has found two new apps, downloaded from Play 11 million times, infected with the same malware family. The researchers from Kaspersky believe a malicious software developer kit for integrating advertising capabilities is once again responsible.
The researchers found Necro in two Google Play apps. One was Wuta Camera, an app with 10 million downloads to date. Wuta Camera versions 6.3.2.148 through 6.3.6.148 contained the malicious SDK that infects apps.
The app has since been updated to remove the malicious component. A separate app with roughly 1 million downloads —Max Browser—was also infected. That app is no longer available on Google Play.
The researchers also found Necro infecting a variety of Android apps available in alternative marketplaces. Those apps typically billed themselves as modified versions of legitimate apps such as Spotify, Minecraft, WhatsApp, Stumble Guys, Car Parking Multiplayer, and Melon Sandbox.