OS X and Viruses
Eric Bergman wrote the following to Macintouch (http://www.macintouch.com/mosxreader10.2pt72.html#sep04)
"Subject: OS X and viruses
I've been using Macs exclusively for my work since about 1990. In those days, there was a modest threat of Mac viruses and I used several of the commercial programs (and the great Disinfectant) for many years. I experienced a couple of minor viruses (MDEF variants) that proved that some form of protective software was a good idea. Several years ago, while still using OS 9, I stopped using any antivirus program because they seemed to cause more trouble than they prevented, and there was such a low incidence of virus activity on the Mac. I continued this policy when I moved to OS X, although I have periodically reviewed the situation to see if I needed to be more careful.
I receive tens if not hundreds of viruses via e-mail every day, each and every one of them impotent on the Mac. I just delete them. Nothing I have read or experienced suggests that there is any reason to buy and use antivirus software under OS X at this time. Nevertheless, everyone who writes on the subject reflexively recommends using something, just because it is safe advice. To do otherwise seems to be very un-PC (so to speak). But if the truth is that there is nothing to be protected from, why waste your money? Or expose yourself to software compatibility problems caused by anti-virus programs?"
Constantin von Wentzel replied:
"Indeed, it is true that there are few Mac-specific Mac viruses, and all of them AFIAK only affect pre OS-X systems. Since the release of OS-X, most of our OS-based security issues could be fixed via software updates from Apple. However, the OS isn't the only avenue to obtain control over a machine.
Note how Microsoft applications are the venue of choice to infect Macs these days. There are literally thousands of platform-independent Macro viruses out there that exploit the pathetic weaknesses in Outlook, Word, and Excel. As MS Office is the platform of choice for business documents and other "compatible" Office suites aren't just there yet, anyone who has to collaborate with folks in the Wintel world practically has to buy MS Office.
Folks who use MS products practically have to use a virus scanner. Otherwise you're opening yourself to a lot of pain and grief later. I welcome that Symantec's latest NAV finally also kills outright Wintel viruses... a omission that was long overdue. Perhaps I will no longer require a version of NAV for my Mac and another one for Virtual PC! Regardless, not being affected by a trojan payload is one thing, stopping even its inadvertent spread is even better. "
Randy B. Singer replied:
"For now at least, there are no viruses that infect OS X. Office macro viruses can run on the Mac, even under OS X, so if you use any of the Microsoft Office applications make sure that you have "Macro Virus Protection" checked in Preferences in each Office application. That will effectively keep them from running. (Even if they do run, many Office macro viruses expect to find Windows software to do damage to, not Mac software.)
However, there are a handful of viruses that can infect OS 9/Classic, even though they are rare.
Also, your Mac can be a carrier of Windows viruses that can infect Windows computers if you share files. So anti-viral software is still useful to have, even if you are running OS X.
In the DealMac forums is a discussion entitled: "Have you ever caught a Mac Virus?" You might like to read the comments. http://dealmac.com/forums/read.html?f=1&i=952391&t=952391
The choices of anti-viral software for OS X:
• Virex 7* (http://www.networkassociates.com/us/products/mcafee/antivirus/desktop/virex.htm)
• Norton Anti-Virus (http://www.symantec.com/nav/nav_mac/index.html ) (NAV installs Kernel Extensions, which have been implicated with causing instability under OS X)
• Sophos Anti-Virus (http://www.sophos.com/pressoffice/pressrel/uk/20030714mac.html) (terribly expensive; meant for enterprise applications)
• Intego Virus Barrier X (http://www.intego.com/virusbarrier/home.html) This product, in my opinion, is the premier anti-viral software product for OS X. It is seamless, safe, effective, and reasonably priced. Though it does not look for, or remove, Windows-only viruses.
• Agax (http://www.defyne.org/agax/)is free, but it only runs in Classic under OS X
* Note that Apple includes a copy of Virex with its US $99/year ".Mac" service.
Another Reader replied:
"The only need I'm aware of for antiviral software on the Mac for OS 8 or later is if the user routinely uses MS Office and frequently exchanges files with other Office users, since it's still a rich source of parasitic scripts. Office can ask the user whether to incapacitate all scripts within a file, which is not an impediment for the occasional incoming file, but power users will want something to screen the malicious scripts out of convenience so that they can continue to use the desired ones.
I stopped depending on antiviral software eight years ago and have not suffered an infection yet - the last few major incidents have been easily dealt with through simple prevention (such as the Autoplay worm, which could be neutered by turning off the autoplay setting in Quicktime preferences).
Even if there was a flourishing culture of virii for the Mac, the sparse market penetration of the systems will limit the extent of damage, even among Mac users. Whether OS X is inherently less vulnerable to infection than Windows (which I doubt), malware writers will generally avoid the platform simply because there's more damage to be wrought by writing for Windows. "
