We know there is a Java problem — most security experts agree with Sophos’ security expert, Paul Ducklin, who has consistently told computer users on any platform to “ switch Java off “.

Almost every Mac is running Apple's version of Java 1.6, and almost every Linux box is running OpenJDK, neither of which are vulnerable to this exploit.

After its hack attack, Apple has released a tool that will shut off malware that may have been installed on hacked Macs.