Pierluigi Paganini October 14, 2017

Crooks have developed a strain of Android ransomware dubbed Doublelocker that both encrypts user data and changes PIN Lock.

DoubleLocker, the name says it all, is a new malware that not only encrypts the Android mobile devices but also changes PIN lock.

The DoubleLocker ransomware was discovered by security researchers from cybersecurity firm ESET.

DoubleLocker is the first-ever ransomware to abuse the Android accessibility feature that implements alternative ways to interact with a mobile device.

The Android accessibility services are abused by several mobile malware including banking Trojan and adware.

“Given its banking malware roots, DoubleLocker may well be turned into what could be called ransom-bankers.” explained Lukáš Štefanko, the ESET malware researcher who discovered DoubleLocker. “Two-stage malware that first tries to wipe your bank or PayPal account and subsequently locks your device and data to request a ransom… Speculation aside, we spotted a test version of such a ransom-banker in the wild as long ago as May, 2017.”

Researchers first detected the DoubleLocker ransomware in May, crooks spread it as a fake Adobe Flash update via compromised websites.

Once the victim launched the app, it requests activation of the malware’s accessibility service, named “Google Play Service”. Once the malicious code has obtained the accessibility permissions, it uses them to activate device administrator rights and set itself as the default Home application without the user’s consent.

“Setting itself as a default home app – a launcher – is a trick that improves the malware’s persistence. Whenever the user clicks on the home button, the ransomware gets activated and the device gets locked again. Thanks to using the accessibility service, the user doesn’t know that they launch malware by hitting Home,” explains Štefanko.