This trojan has the ability to hijack the shutdown process of your Android mobile device so you believe that you turned it off when in fact you haven't. The device will continue to spy on you silently in the background.

PowerOffHijack as it is now being called has been spotted and analyzed by the researchers at the security firm AVG.

First seen in China, the malware spread through Chinese app stores with around 10,000 devices infected so far.

The malware affects versions of Android older than v.5 (Lollipop) and requires root permission to hijack the shut down process. After pressing the power button, the phone displays an authentic shutdown animation, and the phone appears off. Although the screen is black, it is still on.

While the phone is in this state, the malware can make outgoing calls, take pictures and perform many other tasks without notifying you.

If you want to make sure your mobile is really off, take the battery out to be on the safe side.