As ever very much
dependent on your usage/workflow;
As someone who relies on their Mac`s for a living absolutely yes I believe OS X does require protection above and beyond what Apple offers, I see the same question, same rhetoric, over and over;
There are many reasons to run antivirus/malware detection on OS X especially if you are dealing with mixed environments. Passing on malicious code, even inadvertently will do you no favours in a professional environment, let alone your family and friends. What does not hurt OS X may well bring a Windows based system to it`s knees. By far the vast majority of companies that you may potentially work with, or interact with will require a level of antivirus protection, regardless of platform.
You do need to be careful on the choice of application; perviously I ran ClamXav (now a paid app) as the app is extremely light and only looks in realtime at what you specify, equally time has moved on and ClamXav has remained rather static. I now use Avast. Same scenario no impact to performance with a greater scope of realtime protection. Does anyone seriously still believe that running Avast or ClamXav on today`s modern hardware impacts performance? The paid packages I agree are unnecessary on OS X, as the free alternatives are currently perfectly adequate.
Avast or ClamXav will have no impact on a modern Intel based Mac. To have a free, low headroom, accurate scanner and not utilise it, is somewhat stubborn at the very best. The retorts of AV being a resource hog, boils down to one thing, research; Avast or ClamXav will not bog your system down. If it does your system either has other inconsistencies that need addressing, or your hardware is so old it`s well and truly time to upgrade. On my Early 2008 15” 2.4 MBP Avast is simply invisible, there is absolutely no degradation of performance, as for the 13" and 15" Retina`s and now the new 12" Retina MacBook Avast is transparent, same applies to the rest of the Mac`s we own, used professionally and at home.
I have literally decades of work on my systems, and have no intention of losing any data, or suffering any downtime. Antivirus is but one tool in a multilayered security safety net. Lets face it, if and when OS X is compromised it will spread like wildfire, as many fundamentally believe that OS X is invulnerable, then it will be “all over, bar the shouting". I am not entirely sure posts that overly reinforce this false sense of security are remotely helpful to the average user. Even Apple recognises the security threat, however the updates are too slow to be considered a truly preventative measure. As of OS X 10.6 your Mac is running anti malware like it or not courtesy of Apple`s xProtect... Virus/Malware gains traction by exploiting vulnerabilities on unprotected systems. I don't believe for one second that any antivirus/malware detection application is the single security solution for OS X, it is however one of many effective barriers.
I have never had a positive virus hit in all the years I have run drive scans with ClamXav and now Avast, equally I have observed malicious code blocked by Avast`s Web Shield, and removed malware from others systems. OS X is gaining ever more traction and it`s simply a matter of time before someone figures it out, thinking otherwise is simply naive. Avast costs me nothing monetarily, nor time in productivity. This is a safety net that costs little more than a few minutes of your time period.
For those who don't want or need an "active" solution, try Bitdefender Antivirus Scanner
from the App store; it`s free, nonintrusive, and runs only when you want it to. The scanner does not offer much in the line of protection being very much an on demand tool, equally for the majority of OS X users, most just want to validate that the drive is free of malicious code be it related to OS X or Windows. Where Bitdefender`s Scanner excels is detection & simplicity having no daemons or start up agents etc.
You get Bitdefender`s top notch detection in a basic package that you control, however this is not for those who are looking for a set & forget solution, as all scans are manual, and updates only occur when you open the application. That being said an Apple Script, Calendar can easily trigger the application at a given interval. The scanner learns and only scans new & modified files, so in general running a scan for malicious code is swift & painless, once the first pass is competed. Custom scans and Drag & Drop area all present.
Depending on usage/workflow an "active" Malware application is not always the best solution, and there is also the argument that such "active" solutions can be a double-edged sword potentially increasing the "attack surface" against sophisticated threats. Security is very much a multifaceted beast, malware prevention/detection is for both OS X & Windows just one aspect, which is always worth thinking on
There are many compelling reasons to run Avast, Bitdefender or similar, and few if any not too. Personal choices aside I fundamentally believe that suggesting that OS X is 100% safe to all and does not need such tools is very much a step in the wrong direction; not all are technically minded, neither do all users who may have access to systems follow safe computing rules and guidelines. The vast majority simply point and click to get to where or what they want, Avast or ClamXav simply serves as a barrier to protect those that are unaware, and some cases unconcerned, ultimately such safeguards protect the community as a whole.
I also recommend that people install Malwarebytes
for Mac, as has been frequently stated malicious code is ever evolving and we as a community should be equally fluid.
A significant aspect for those of us who rely on our Mac`s for income is downtime; spending hours tracking down malicious code is simply a negative financially to me, as ever prevention is far more effective than cure. In the field should my hardware fail to perform due to a software issue, it can cost me up to and above the price of the Notebook in use, for everyday it`s down, the math is simple.
Install, don’t install it`s down to you...