Warnings have been sounded about an Android app which hackers are using to hijack smartphones in order to run up large texting bills without the knowledge of their owners.

Piracy software developer Symantec has warned of Steamy Window, a free-to-download which has been modified by Chinese hackers, and then re-released.

According to ComputerWorld, The hackers have released the app with a Trojan Horse – ‘Android Piapps’ included in the app’s code, which is then being offered by third party app download areas.

Once installed, the app allows the Trojan Horse to then install other applications, which allows criminals to navigate to websites and send text messages to premium rate numbers, making them money.

Meanwhile, the Trojan is also able to block incoming texts on the person’s phone.