A new Android malware tool spotted by security vendor AVG earlier this month has served another reminder on the dangers of downloading mobile applications from insecure third-party app stores.

Stealthy Thief

The malicious software is designed to fool Android smartphone users into thinking their devices have been shut down, when the devices actually remain powered on and open to abuse. The malware can be used to spy on the owner, steal data from the device, take pictures and perform other surreptitious acts without tipping off the user.

Researchers at AVG reported seeing the Android malware being distributed through several Chinese application stores for Android. Around 10,000 phones are believed to be infected by the Android malware so far.

Android Malware Shutdown Process

The malware, which affects Android KitKat and older versions of Google’s mobile operating system, basically works by hijacking the device shutdown process. According to AVG’s description of the problem, a phone infected with the malware displays seemingly authentic shutdown animations and text when the user presses the power button.

After going through what appears to be a normal shutdown routine, the screen goes dark and the phone appears to be off. In reality, the malware gains root-level access and injects itself into a process that is invoked when a user presses and then releases the power button. In order to fool users into thinking the phone is really switched off, the malware also hooks into some broadcast services so functions such as recording calls or transmitting messages can be done stealthily.

“Most of us have seen Hollywood movies where hackers trace and spy on mobile devices, even though they are switched off,” AVG noted in its blog. “Like most things in spy movies, we disregard it as fiction.” However, this newly discovered Android malware challenges that perception.

AVG did not offer any explanation on the vulnerability the malware exploits to gain root-level access on compromised devices.

A Familiar Problem

The new threat highlights the problems users can run into when using third-party stores to download mobile applications, particularly for Android. According to Forbes, 97 percent of all mobile malware is currently on Android systems. An overwhelming majority of the malware is distributed through doctored or outright malicious applications hosted on third-party mobile application stores.

In many cases, cybercriminals infect popular programs in these application stores with malicious software that users unwittingly download on their devices alongside the legitimate software. For instance, popular Android game applications hosted by third-party application stores often contain hidden malware users download onto their system when acquiring the game application.

Online stores such as Mumayi, eoeMarket, Android159 and liqucn host a relatively high number of malicious programs, according to a Forbes analysis of the state of Android malware. Google Play’s store, on the other hand, accounts for less than 0.1 percent of malicious Android applications. This means users who only download apps via the Google Play store often face fewer security problems.

Google, too, has contributed to the problem by making its applications relatively hard to obtain via the Google Play Store in certain geographies. The countries where software developers can actually sell their applications through Google Play remain relatively low, forcing users in such regions to go find the applications they want via risky third-party download sites.

Image Source: iStock