The malware family Brain Test, unfortunately, has made a comeback. Some variants attempt to gain root privilege, and persist factory resets and other efforts to remove it, especially on rooted devices. Google quickly removed these 13 apps from the Google Play Store, but we are continuing to monitor for new variants. A simple factory reset (in other words, using the ‘Factory Reset’ option from the Settings application on an Android device) is not enough to remove the malware, as factory resets do not clear the /system partition.”]