Researcher Vitor Ventura said in a blog post that the trojan had a number of built-in capabilities, but was extremely flexible, making it an effective aid for attackers.

GPlayed derived its power from adaptability after it had been deployed, Ventura said; the attacker was able to remotely load plugins, inject scripts and even compile new code to be executed.

"Mobile developers have recently begun eschewing traditional app stores and instead want to deliver their software directly through their own means," Ventura said, in a reference to the popular game Fortnite which was not distributed through the Google Play store.

"But GPlayed is an example of where this can go wrong, especially if a mobile user is not aware of how to distinguish a fake app versus a real one," he added.

GPlayed had the capabilities of a banking trojan and could also spy on a user; this meant it could harvest banking credentials or monitor the location of a device.

Ventura said the only sample was found on public repositories and almost seemed to indicate a test run to determine the detection ratio of the sample.

"We have observed this trojan being submitted to public anti-virus testing platforms, once as a package and once for each DLL to determine the detection ratio. The sample analysed was targeted at Russian-speaking users, as most of the user interaction pages are written in Russian," he said.

"However, given the way the trojan is built, it is highly customisable, meaning that adapting it to a different language would be extremely easy. The wide range of capabilities doesn't limit this trojan to a specific malicious activity like a banking trojan or a ransomware. This makes it impossible to create a target profile."

Above, right: The GPlayed trojan has an icon very much like the Google Play Store and can be seen on the left in the centre of the picture. Courtesy Talos