Variants of the malware have been popping up on third party online markets for months and, until now, they were only capable of sending text messages to premium rate numbers on behalf of the user.
But the latest variant - MouaBad.p - also makes the device place calls to premium rate numbers, again with the user being none the wiser.
"In addition to never-before-seen functionality, Mouabad.p is particularly sneaky and effective in its aim to avoid detection," the researchers pointed out. "For example, it waits to make its calls until a period of time after the screen turns off and the lock screen activates. It also end the calls it makes as soon as a user interacts with their device (e.g. unlocks it)."
"In theory, this dialing functionality could also be used for other malicious purposes such as remotely spying on conversations within the vicinity of a device microphone, or simply running up a victimís wireless bill," they also noted."
But the good news is that MouaBad.p is incapable of modifying call logs, so a look at the call history will immediately indicate that something shady has been going on and, ideally, alert users to the presence of malware on their device.
Another good news is that, for now, the C&C server directing the actions of the malware is currently down.