SLocker, aka Simple Locker, is a mobile ransomware that locks victims mobile devices and requests the payment of a ransom to unlock them. The code of the SLocker Android malware has been leaked online for free, allowing crooks to develop their own variant of the threat. SLocker was first spotted in 2015, it is the first ransomware to encrypt Android files. The malware impersonates law enforcement agencies to convince victims to pay the ransom, it infected thousands of Android devices in 2016.”]
Source: https://securityaffairs.co/wordpress/61323/malware/slocker-source-code.html