Attacks on Flash, Java, QuickTime and various other ubiquitous apps have been a major concern for Windows users for the better part of a decade. The Flashback malware that has been exploiting a vulnerability in Java has brought the reality of attacks on third-party applications to the fore for Mac customers. Java is everywhere on the Web, and many non-technical users aren t necessarily aware of the need to update it frequently or of the exalted place it holds in the hearts of attackers.
Source: https://threatpost.com/many-mac-users-running-vulnerable-java-versions-041212/76438/