The following has been pulled from:
http://www.macworld.co.uk/feature/mac-software/mac-antivirus-internet-security-software-malware-review-3523842/
But the bottom line is that YES, you need anti-virus software on your Mac! I run Sophos, but there are several other options, many of them are free.
http://www.sophos.com/en-us/products/free-tools/sophos-antivirus-for-mac-home-edition.aspx
Best Mac antivirus software: Do Macs need antivirus & internet security software?
First things first: do Macs need antivirus software at all? Let's consider two of the most commonly heard views on the subject of Mac security:"Macs are essentially secure and are immune to viruses."
"Macs are like any other machine - if they're connected to the web, they're a malware target, and just as vulnerable to cyber attack as any other computer."
Somewhere between these two statements lies the truth. Macs are not immune to cyber attack, and assuming that they are is a dangerous game to play. But what we do know with certainty is that when compared to the most widely used and exploited computing platforms - Windows for desktop PCs and Android for mobile phones - the Apple Mac has all but evaded the widespread attention of criminals.
Most malware developers seek to infect and control computers for profit, pursuing platforms that are the most popular by number and least secure by design. For these reasons Mac OS X is still far from top of their to-do list.
And OS X is itself more difficult for cybercriminals to target. It's Unix-based, for one thing, and Unix offers a number of security features built in - such as the way that executable code and data is stored in separate folders. This is why deleting an app on a Mac is so simple.
Nevertheless, dangerous malware for OS X does exist, in limited numbers. It's perhaps a sign of quite how limited that when an outbreak of a 'Mac virus' does occur, it makes front-page news on tech sites; sometimes it's even discussed in international news channels. Especially when the victim is a high-profile user such as Google or Apple itself, as was disclosed in February 2013 when a Trojan broke these companies' defences, aided by that old perennial of malware facilitators: the cross-platform Java software.
Whether malware-detection software was used at Apple and Google campuses we do not know, but targeted attacks at gateway individuals will typically use malware that is not currently on any AV (antivirus) firm's blacklist; or use zero-day exploits in the PC operating system, or indeed any application running on it.
Sadly for Mac users everywhere, the widespread adoption of Apple's desktop computing platform by keenly targeted companies like Google - which has migrated away from Windows almost entirely after a wave of spearphishing attacks in 2009 - means that criminal and state-run hackers will be honing their techniques specifically against OS X now more than ever.
Bottom line: Despite what some analysts have argued, Macs are fundamentally safer from malware and other internet attacks than PCs. Architecturally Unix-based OS X is considered more difficult to crack than rival OS platforms, but a larger factor is the simple fact that (for reasons of market share and risk-reward calculations) less malware is written to target Macs. However, there are Mac viruses out there, and it would be a mistake to assume that your Mac is completely immune to attack.
For more on this topic, see Do Macs get viruses? and Apple removes claim that 'Macs don't get PC viruses'. And read more about why Macs are safer than PCs here.
Best Mac antivirus software: Spyware
A word about spyware. This was a popular form of intrusion on Windows PCs up to around ten years ago but is now rarely discussed or highlighted by antivirus software. The reason is that spyware is now more pervasive and used against every internet-connected platform, whether laptop or desktop, smartphone or tablet. It's almost reached respectable status, in that many people aware of the problem are hopelessly resigned to its use.So now, spyware is employed by commercial companies in order to track web users through more insidious processes than just installing a secret .exe on your PC. Spying and tracking your computer use is now standard operational procedure for social networks and thousands of web-analytics startups, all focused on reading and writing your browser cookies, your Flash cookies, hiding invisible tracking pixels and deploying assorted JavaScript tricks, triggered for example by clicking 'Like' or '+1' buttons.
To reduce the effects of privacy-invading web tracking spyware on your Mac requires a different strategy than installing antivirus software. Good starting points would be to use Ghostery or Disconnect browser plugins, with a cookie manager such as Sweet P Cookie.
Less than half of Mac owners have antivirus software installed
Best Mac antivirus software: Privacy, user data and free software
Similarly, if you're turning to security software for your Mac to help combat remote surveillance of you, be sure to ask how an antivirus company is treating your data. Most antivirus programs are reasonably up-front in acknowledging that they will - usually with your opt-in consent - check every web page you visit, harvest suspect files from your computer for their own analysis, and collect what they deem suspicious emails, including their contents.Such data mining is more prevalent in 'free' software, where the developer can recoup their investment by using you the user to harvest more data on their behalf. But even paid-for AV software will have some form of 'user community' or customer feedback system which collects data from you.
See also: Why Google is the world's biggest threat to user privacy, and only Apple can help
Best Mac antivirus software: Mac security software group test
We assembled a group of six Mac malware-detection suites, half available to download for free, half based on the traditional yearly subscription model. The former group carry the usual caveat about 'free' products, whereby you may be paying through other means, sometimes agreeing to have your web use monitored or to having your files uploaded to the vendor.Ideally antivirus software should detect, and remove where necessary, each and every piece of malware that comes close to your computer. It should do so without ever making the mistake of wrongly identifying innocent files as malware. It should do so transparently enough that you are not disturbed by notifications that it's just updated itself, or needs registering, or in other ways needlessly tries to grab your attention. And finally it should not slow down your computer in any way while it is operating silently in the background.
Unfortunately by these definitions there is no such thing as ideal security software. All current software available to Mac or Windows is afflicted by one or several issues from that wish list.
To ascertain the most important aspect of actually stopping and detecting malware, we turned to Mac anti-malware specialist Security Spread, a website that publishes full lab tests of antivirus software for OS X. We used the results of its last round-up in April 2014, including an application's ability to detect over 400 strains of real malware installers, installed malware traces, and propensity to falsely accuse innocent software of evil intent.
We also looked at the impact of running security software on your Mac, which may be far more debilitating than is commonly realised. Some tasks took a worrying 14 times longer with real-time scanning enabled.
Best Mac antivirus software: Software reviews
We looked at six of the best Mac antivirus & all-round security suites on the market right now. Below are summaries of our reviews, but click through to read the full review and see all our detailed test results.Avast Free AntiVirus for Mac 8.0 antivirus software review
Avast Free Antivirus for Mac 8.0 is free and
offers decent malware protection. Avast could make a good fallback for
monitoring known Mac malware, although our tests suggest it can slow
your Mac to a crawl in daily activities when simply running in the
background.
| FREE (for non-commercial use) | Read the full Avast Free AntiVirus for Mac 8.0 reviewAvira for Mac antivirus software review
Avira for Mac is a capable antivirus
software suite that didn't cause as much of a slow-down on our test Macs
as other suites here. Plus, the German and family-owned company doesn't
currently seem to subsidise its freemium business model by selling user
data.
FREE | Read the full Avira for Mac reviewClamXav2 AntiVirus review
ClamXav2 works well and is regularly updated
by its volunteer developer. It was the slowest antivirus suite in its
scans but has no real-time scanner component to slow down day-to-day
work on your Mac.
| FREE | Read the full ClamXav2 AntiVirus reviewESET Cyber Security for Mac antivirus software review
ESET's Cyber Security for Mac is ideal for
those who like to tweak and optimise - not to mention a sophisticated
security application with good malware detection.
| £30 per year (one Mac) | Read the full ESET Cyber Security for Mac reviewIntego Mac Internet Security X8 antivirus software review
Intego's Mac Internet Security X8 suite is
simple to set up and caused minimal Mac slow-down. It consistently
scored highly in our malware-spotting tests.
| £40 per year (one Mac) | Read the full Intego Mac Internet Security X8 review
Kaspersky Internet Security for Mac antivirus software review
Kaspersky's Internet Security for Mac
software offers reasonable performance but tended to be a little
unstable. Nevertheless, it proved relatively capable in our
malware-protection benchmarks. There are better alternatives.
£39.99 | Read the full Kaspersky Internet Security for Mac review
Best Mac antivirus software: Conclusion - which is the best Mac internet security suite?
Do you need to run a full-time virus scanner on your Mac? The answer for most users today is still probably no, although there are people and organisations for whom the added level of security is worthwhile - financial institutions, cautious corporations, along with security researchers trawling the web's underbelly.Apple does include some rudimentary malware protection within the Mac operating system, Xprotect, and this will screen incoming files for a limited number of Trojans that have cause some trouble in recent years. As of June 2014, we noted 37 different malware signatures on Apple's wanted list, representing some of the most annoying Trojans that have troubled some users. But if you're serious about security you will need software that has more timely updates and stops the variants that aren't already on this watch list.
Running antivirus all the time in the background can have a remarkable effect in slowing down your Mac's performance, so you may like to consider running regular system scans when you're not using the machine and disabling real-time protection at times when you don't want to wait ten times longer than normal for some tasks to complete.
From the group we reviewed here, the three free antivirus software packages all proved reasonably adept at spotting malware, although open-source ClamXav 2 can only scan on-demand. Nevertheless you can set a 'watch folder' for it to keep tabs on at all times. Avast is consistently near the top several recent lab tests by Security Spread, although we also found it somewhat intrusive in its privacy policy, with strong links to companies known for breaching personal privacy laws. Avira seems to strike a better balance, with high malware detection rates, a clean and simple interface and stated compliance with German privacy laws.
Of the paid-for antivirus software packages we reviewed, Kaspersky Lab's latest was perhaps the most disappointing. The company has a good pedigree in chasing down Windows malware, and the product has improved since this user last tested five years ago. But it still proved a little unstable at times. Its file fingerprinting could help mitigate against slow repeated scanning of the same directory, although this may be of little benefit if the results are not cached between launches.
Our two favourite security application from this group were ESET Cyber Security and Intego Mac Internet Security X8 - but for quite different reasons.
ESET appealed to our tweak-happy side, giving many options for fine-tuning the application to balance malware-seeking efficacy against resource hogging and false positives. Even tested with default settings it showed some of the least intrusive impact on Mac processor use. It also features an easy but effective external volume utility that can block most usual data ports, or warn on USB thumbdrive insertion, for example. The company has obviously put a lot of time into designing and developing its Cyber Security software for Mac users, and supports it well. In malware detection terms it's a few down from the top but like most will likely keep you safe from 9 out of 10 known Mac threats.
If you want antivirus for your Mac that has the best chance of spotting incoming danger, the consistently highest scoring solution looks to be Intego VirusBarrier. It is also rated best for picking up on nasties that have already distributed themselves around your /private areas. Now packaged with NetBarrier for the entry-level Mac Internet Security X8 product, the software is also with Kaspersky Internet Security for Mac the most premium-priced at £40 every year. The software's stability, limited resource diversions and ease of use commend it to most potential users of Mac security software.
Best Mac antivirus software: Further reading and alternative Mac security suites
It won't have escaped eagle-eyed readers' attention that the above six Mac antivirus products are not the only ones available to buy. While these are the six we focused on in our lab testing, here are older reviews of some alternative Mac security suites:Norton AntiVirus 12 for Mac review (reviewed December 2012)
McAfee Internet Security for Mac review (January 2012)
Sophos Anti-Virus for Mac review (February 2011)
These may give some guidance as to the general reputation and quality of software produced by rival security firms. Bear in mind, however, that these reviews are a few years old, and that the importance and frequency of patches and updates makes it vital to check up-to-date reviews of security suites. The 6 antivirus suites reviewed above were all reviewed at the same time, under the same conditions and using exactly the same methodology, and we would recommend choosing your Mac security software - if you choose to use one - from that list.
Finally, for more information on Mac security, take a look at this feature by our colleagues at PC Advisor: Do Apple Macs need antivirus? OS X security explained, and for a general roundup of recent developments in the industry, see 5 cool new security research breakthroughs.