Apple customers who downloaded the latest version of Transmission likely downloaded a new family of Ransomware that targets OS X installations instead. The problem was discovered by Unit 42 researchers at Palo Alto Networks. The malware was embedded within the DMG file itself, bypassing Apple’s Gatekeeper protection. Once installed, KeRanger will wait three days before contacting a C2 (Command & Control server) via the Tor network. If contact is made, the system is encrypted and the ransom demanded is $400.00 USD.”]
Source: https://www.csoonline.com/article/3041080/ransomware-developers-target-apple-customers.html