A type of malware that locks computer files and demands a fee for their release has successfully targeted Apple computers.
The security researchers from Palo Alto Networks believe it is the first time ransomware has appeared on Macs.
The KeRangers malware was hidden in a version of a BitTorrent client called Transmission.
The makers of Transmission and Apple say they have taken steps to stop the malware spreading.
It is not clear how many people were affected.
Transmission is a program that lets people download and share BitTorrent files - often music or movies - with other users' computers.
After being informed of the malware, Apple revoked the developers' certificate on the infected software to prevent it from being installed if people downloaded it
Apple Macs hit by ransomware 'for first time' - BBC News
The security researchers from Palo Alto Networks believe it is the first time ransomware has appeared on Macs.
The KeRangers malware was hidden in a version of a BitTorrent client called Transmission.
The makers of Transmission and Apple say they have taken steps to stop the malware spreading.
It is not clear how many people were affected.
Transmission is a program that lets people download and share BitTorrent files - often music or movies - with other users' computers.
After being informed of the malware, Apple revoked the developers' certificate on the infected software to prevent it from being installed if people downloaded it
Apple Macs hit by ransomware 'for first time' - BBC News