A particularly devious new Android malware can make calls or take photos even if you shut the device down, according to security research firm AVG.

To achieve this, the malware hijacks the shutting down process — making it appear as though your Android device is shutting down. You see the animation, the screen goes black, but the phone is actually still on.

In this state, the malware can use the phone to send your messages to a third party, record a call or take a photo, essentially turning your phone into a device that spies on you.

AVG, which posted code excerpts showing some of the malware's functionality, names this threat Android/PowerOffHijack.A. According to the company, it infects devices running Android versions below 5.0 and requires root permissions in order to act.

The company spokesperson told us some 10,000 devices were infected so far, mostly in China where the malware was first introduced and offered through the local, official app stores.

The latest AVG antivirus products can detect this threat, but the company still advises users to take the battery out of their phone if they really want to be sure their phone is off.

Updated Feb. 19, 07:28 with comments from an AVG spokesperson.