Flashback/Flashfake is a family of malware for Mac OS X. In March 2012 around 700,000 computers worldwide were infected by Flashback. The infected computers are combined in a botnet which enables cybercriminals to install additional malicious modules on them at will. The use of exploits to distribute Flashfake was first detected in February 2012; exploits dating back to 2008 and 2011 were used in those attacks. The attack involved an attempt to execute four Jar files (Java applications) Three of these were exploits for Java vulnerabilities; the fourth was disguised as a legitimate application.”]
Source: https://securelist.com/the-anatomy-of-flashfake-part-1/36423/