For some time now, many people have believed that viruses and malware on a Mac was impossible. This is not true. The most recent threat to mac users goes by the name Dok. Dok targets all versions of Mac OS, and will completely take control of your mac if you let it. Also, at this moment, anti-malware software is not picking up said virus. But for the time being the only way for this malware to infect your computer is if you open the Zip file attached to an unfamiliar email.
Once Dok is successfully installed to your Mac, it gets access to all communications going through your computer, including those encrypted by SSL. The attacker does this by secretly redirecting traffic through a malicious proxy server. Here the attacker can monitor your data and pick out anything that they might want. When complete, the software deletes itself.
Source : http://www.pcmag.com/news/353411/dok-malware-takes-complete-control-of-your-mac