Security should always be a number one priority, we're talking about tech here, but this actually applies to pretty much anything. If your computers, smartphones, tablets, smartwatches… are not secure, then you better not use them. Luckily, companies do pay attention to security, but the question is, do they do enough? Malicious software (malware) has been creeping in pretty much everything these days, including Android OS. Still, if you're careful enough with how you use your device (what you install on it).
That being said, it seems like a malware has crept into the Google Play Store disguised as a game. The name of that game is 'Brain Test' according to the source, and it has been attacking devices since August. It was initially thought that this app has been pushing ads onto the devices it is installed on, but that might be only half the story. According to the source, the app actually causes more damage in the backend, and it can reportedly even avoid Google's vetting system, which his a serious matter. This malware can, reportedly, acquire root access. 'Brain Test' can basically take control of your device, and the app has been installed by over a million users before it was removed back in September.
"This sounds like another case of phone carriers and manufacturers leaving users vulnerable to attack. Unfortunately, apart from a few supported Nexus devices, Google has little to no control over the Android updates pushed to handsets. This means that information about vulnerabilities becomes public as the Android open source project receives fixes, but the vast majority of users do not receive these fixes. This allows rogue apps to take control of phones and tablets," said Craig Young, Computer Security Researcher for Tripwire.
There is only one way to rid yourself of this malware, and that is by flashing your device. You'll basically need to reinstall your ROM (be it official one or not) in order to fully delete this malware. We're hoping to see less and less apps like this hit Google Play Store in the future, because this malware is not something you should take lightly.