Kaspersky Lab experts have calculated the chances of a malicious program making it onto a Mac OS X device. In August, the probability of unwanted encounters with malware was about 3%. Compared to the 21% infection risk facing Windows users, the situation with Macs seems much more relaxed. However, if you translate this into the number of potential incidents, the problem no longer seems so trivial– according to Kaspersky Security Network data, an active Internet user could find malware getting onto a Mac OS X device at least 10 times a year.
In the first 8 months of 2014, Kaspersky Lab recorded almost 1,000 unique attacks against Mac devices. These attacks are grouped into 25 main families
There is a roughly 3% chance of a Mac OS X computer becoming infected.
There are 1800 samples of malicious Mac OS X files in Kaspersky Lab’s collection.
I use to use Apple Mac for 3-4yrs and I found Kaspersky to be by far the best antivirus for Mac's. It even comes with a URL scanner so you then know if a website is harmful etc., give it a try, the UI is also well laid out and easy to understand. I have tried Intego but it was poor to say the least.