Are there viruses and Trojans that afflict Macintosh, witness Apple’s periodic release of security fixes to counteract them?
First, that isn’t true, regarding viruses. To date, there are no known viruses that specifically target Mac OS X. Last week’s “trojan” [note: this was written end of March 2005] was nothing more than an application with a different icon and misleading name that displayed a dialog box (which was an example posted to a USENET Mac programming group to illustrate this fact that has been known and possible on Mac OS for over twenty years; an antivirus vendor apparently thought this an appropriate time to dress it up, incorrectly, as some new, terrible exploit easily adapted for malicious means, when in reality it’s nothing more than an application).
If you’re referring more broadly to security issues in general, almost all of the security and security-related updates for Mac OS X to date have been updates for primarily server-type services that ship with the OS, all of which are disabled by default, and the lion’s share of which are never even enabled, much less touched, on the vast majority of systems. I’m not saying that they should be ignored, but Apple’s comprehensive and swift response to the most minor security issues does not rise to the level of the staggeringly numerous, sometimes completely automated, remote exploits, worms, and so on for Windows. It is no longer possible to even get through a full installation Windows XP on a machine connected to a public network without it being exploited before you even have a chance to patch it.
It’s definitely possible for Mac OS X to have viruses, worms, trojans, and other malware - Mac OS X is not invulnerable, and no sensible person would claim it to be. But the underlying philosophical design principles are fundamentally more secure than Windows, period. Since the major ingredient for the success of a worm or virus is some ability to spread, witness the fact that there is no way with anything built into Mac OS X to perform automated propagation of a virus, and no current known ways to exploit a machine remotely, not to mention that potentially exploitable network services are disabled to begin with anyway (and remain that way unless explicitly enabled), a stark contrast to Windows. Any hope for automatic propagation would require a comparatively high level of sophistication, and perhaps even its own mail server - not to mention some intrinsic vulnerability to exploit. On the other hand, there are still, to this moment, unfixed vulnerabilities in certain versions of Outlook that will spread certain virus variants simply by previewing a message, and nothing more. There is simply no equivalent to this on any other platform. Microsoft’s track record and attitude on security (though admittedly much improved) versus other vendors speaks volumes on this topic.
It takes work and thought to do security, and do it right. Ease of use and security aren’t mutually exclusive. The key is to make security easy to use, and Apple has so far been on the right road with Mac OS X.