KeRanger takes the claim of being the first fully functional ransomware program targeting users of Apple Macintosh computers and laptops. KeRanger is capable of encrypting a Mac user s data and then demanding a ransom of 1 Bitcoin, which equals about $400, in order to provide the user with a key to unlock the data.
The initial strain of KeRanger is designed to encrypt more than 300 different file types on Mac computers, and it replaces these file with encrypted versions. KeRanger waits three days after installation to begin the encryption cycle, in an attempt to evade some antivirus tools from detecting KeRanger as a malicious file.
KeRanger Discovered in Transmission Bittorrent Update
KeRanger appeared in the wild on March 4, 2016, as part of the latest version of the open-source Transmission BitTorrent client. The malware was identified within six hours of the update, and the Transmission project was able to post a warning on its website alerting users to download and upgrade to version 2.92, as the earlier version 2.90 release contained the OSX.KeRanger.A ransomware.
Fortunately, this gave users of version 2.90 time to upgrade Transmission and uninstall KeRanger before it started its encryption routine, which minimized the potential damage KeRanger could have inflicted on many Mac OS X users.
Incomplete FileCoder Ransomware Preceded KeRanger
While KeRanger takes the claim as the first functional Mac ransomware piece of malware, it s not the first ransomware attempt initiated against Mac OS X users. An unfinished piece of ransomware dubbed FileCoder was discovered by antivirus firm Kaspersky Lab in June 2014. FileCoder appeared to have been an early test version of a malware program that had not been completed.