The "Joker" malware is found to exist within yet another Android app
Joker malware is a form of Trojan that reportedly downloads a secured configuration from a command-and-control (C&C) server in a manner masked by the installation of an infected app. The hidden software then installs a follow-up component that steals SMS details under the guise of the host's interaction with ad websites.
The aim of this infiltration appears to involve gaining the access necessary so as to allow automatic sign-ups to premium SMS services. Joker also reportedly steals contacts and text messages. It had been found on a rash of Android apps back in September 2019, but not been heard of since. Unfortunately, this may no longer be the case.
Int App Lock had been marketed as a per-app PIN-setting service for Android. The security group Pradeo Lab claims to have found Joker on this app. Luckily, the organization has contacted Google about this issue, which led to the app's suspension from the Play Store. However, users who still have the offending software installed are best off removing it without delay.