It says some users have had photos taken of them without permission, before their phones were locked by the people behind the software.

Security experts have warned that a popular pornography app may be tricking users into giving away more than they bargained for thanks to some troublesome ransomware. It’s not unheard of for legitimate apps to need to be downloaded in this way – Amazon’s Android app for Prime TV, for example, but you should know better than to start installing random apps that promise you porn from anywhere on the internet.

Researchers at security firm Zscaler, have found a malicious porn app that gains access to the owners smartphone camera.

‘When the victim starts using it, the app silently takes a photo of the victim, which is then displayed on the ransomware screen, along with the ransom message. After that, it locks the screen and demands a payment of $500 before it will let you use the device again. “Intel Security’s most recent Threats Report uncovered that ransomware shot up 127 percent in the past year alone”.

“One of the reasons for the increase is that it’s very easy to make”, said Raj Samani, chief technology officer for Intel Security in Europe. “One group we tracked made more than $75,000 in 10 weeks”, Samanji said.

Apps like this rely on the embarrassment factor.

The app was not available from vetted storefronts such as Google Play, but could be installed directly from a webpage. If you have been infected the malware can be removed by booting the device into safe mode. Some ransomware threatens to delete your photos, videos and documents so back up your data.

Even if you switch your phone on and off, there is no way to uninstall the software.

First off, you need to download the app from outside the Google Play app store, which removes all the safeguards that go along with that. “And if you receive an app download link in an email, don’t click it”.

Zscaler has told users affected by Adult Player to restart their smartphones in safe mode, which loads the device’s operating system without running third-party apps.