Experts say an Android phone app that takes a photo of the user and holds their device ransom for $US500 ($A722) is high-tech blackmail.
The app, called Adult Player, appears to offer users pornographic images but instead secretly takes pictures with the front facing camera, technology blog ZScaler says.
The app then holds the phone hostage and pressures the victim to pay a $US500 ransom through PayPal.
Suelette Dreyfus from the University of Melbourne says `ransomware' has been a growing field since it erupted a decade ago.
"There was an estimate by US law enforcement that the ransomware was netting about $150 million per year for that criminal industry," Dr Dreyfus told AAP on Tuesday.
She says the Adult Player app ransomware is very sophisticated.
"Not only does it block your phone but it preserves data you don't want to exist and is more on the blackmail end," Dr Dreyfus said.
This type of scam malware through a personal computer is nothing new, but its emergence through phone apps is a concerning trend.
The thought of the app releasing private photos to a user's contact list may be enough to coerce them into paying the ransom.
But the question remains as to whether the malware will stop collecting data after the ransom has been paid.
ZScaler says the app will still be on the device after a reboot if the user tries to delete it and has included a step-by-step process on their website to remove it.
A simple way to protect against malware accessing your camera is to place a sticker over it to avoid apps capturing private moments without permission, Dr Dreyfus said.
