After two years of police-themed ransomware headaches for desktop owners, the extortion scam has arrived for Android.
Police ransom malware that has locked up desktops to extort around $100 from victims across the globe now has a greedier Android variant that seals the mobile device until a fee of $300 is paid up for an alleged cyber-offence.
The malicious Android file, discovered by independent researcher @kafeine, uses many of the same traps as its desktop cousin to extort cash, including locking the device down and displaying a message supposedly from law enforcement that demands payment in order to regain access. The US version is currently asking for $300.
Fortunately for Android owners, unlike ransomware for desktops, the Android APK file that will lock the device doesn’t automatically install upon visiting a website. It’s also not being distributed through Google Play and would require settings on the device to allow downloads from unofficial sources.
Instead, the threat is currently being spread via a network of un-compromised websites (such as fake porn sites) called a "traffic distribution system". TDS networks are used by criminals to distribute malware, rather than using real websites that have been compromised to do the job.
While the APK file requires user interaction to install, it will download automatically. Android browsers that land on the TDS will be redirected to a website that, according to Kafeine, “will push the download of the APK to the mobile without interaction.” After downloading, the device will ask the user if they want to manually install an app called “BaDoink”, which is presented as a “mobile bestiality” app.
In other words, Android devices are more difficult to infect than desktops. However, should a victim choose to install the app, it may be difficult to do much with the Android device until the fee is paid.
“The locker is kind of effective. You can go on your homescreen but nothing else seems to work,” said Kafeine.
Launching the browser, calling apps, or inspecting the list of active tasks “will bring the Locker back”, the researcher noted.
While security experts advise victims of ransomware not to pay the extortion, victims that do install this particular app may be more inclined to cough up the fee than report the incident to police.
A recent threat assessment by the EU’s law enforcement agency, Europol, noted “exponential growth in police ransomware attacks in the EU”. One reason why victims might not report the crime is that they are “ashamed”, since many had been in contact with pornographic websites.
The app also comes with a number of noteworthy access permissions, including “prevent phone from sleeping”, in addition to “run at startup” and “full network access”. It also has the right to “read phone status and identity”.
Like desktop based police ransomware, the Android malware has multiple lock page designs that contain the insignia of law enforcement local to the region of the victim’s IP address. The Android malware has a total of 31 designs for victims in Europe, the US and Australia.