Monday, December 1

Apple recommending OSX anti-virus? Is this true, do I run out and buy it?

As others have pointed out on November 21st, Apple silently recommends anti-virus products for OSX.
"Apple encourages the widespread use of multiple antivirus utilities so that virus programmers have more than one application to circumvent, thus making the whole virus writing process more difficult."

This isn't as clearly written as many of the other Apple support articles, and there are a few related topics which should have more clarity.
  1. Who is the audience for this advice? Is it the majority of non-technical mac owners who are unaware of the types of malware? Or is it all OSX users?
  2. Are they also recommended that multiple, as in more than one, anti-virus utilities be used at once? If so how many are recommended, two, three?
Apple also has a handful of other references to anti-virus on OSX 10.5. As stated in a support article from April:

"6) Check for Viruses
Macs are far more less likely to get a computer virus like Windows PCs are prone to but that doesn't mean it's impossible. If you don't already have antivirus software, you may want to consider making a purchase. If you have the software installed, be sure to keep your virus definitions up to date—you can find the latest updates on your software manufacturer's website."

Again Apple recommends considering purchasing this software, but doesn't supply any criteria to help a user with this consideration.

When looking at OSX 10.5 security features Apple provides a brief description of ways that Leopard protects the user from potentially harmful practices of downloading and running malicious programs, but other than sandboxing and alerting users to potentially unsafe downloads, there isn't much information in this marketing material.

Digging a bit deeper though, shows slightly more information. Apple has published a security tech brief for 10.5. This document provides a really good description of each of the security features in 10.5. I've extracted a few which in my opinion are the most relevent to preventing malware infections - which most anti-virus software helps to do.
  1. User permissions model. By default OSX operates with restricted user access (unless you configure it otherwise). This means that regular users, and even administrative users, do not have access to modify items in the "system" domain without additional authorization. So even if Safari is susceptible to some vulnerability, or a bad email attachment is run, it likely won't be able to escape the user's limited access.
  2. Runtime Protection. OSX like other modern operating systems does provide protection from common virus behaviour like buffer overflows and other memory and execution vulnerabilities. 10.5 uses execute disable, library randomization and sandboxing to keep applications from hijacking system execution.
Still, nowhere in this more detailed tech brief does apple mention the recommendation to install and use anti-virus software. So where does this leave us? Should we follow Apple's recent, albeit quiet, advice to install ClamavX?

My personal opinion on this, is that anti-virus has become a more of a security risk than control. Wha?! Before you discredit this post let me explain.

My opinion is based on anti-virus software use by 99% of the Internet community, people who haven't been educated on how virus' work, are spread, and cause damage. These people likely have been affected by a virus infection in the past, and after a co-worker calls them to inform them that they've been sending infected messages out, take their computers to the local big-box retailer and they sell them an anti-virus product after re-imaging their PC.

Further more, lets also assume that the best of these anti-virus products are effective in stopping 99% of the virus's encountered, which is ridiculously high but illustrates my argument well.

For this average user, they have now been comforted that as they open the email attachment from the prince of Nigeria, that the anti-virus software will catch and protect them from the malicious program which will make their PC a part of the growing population of botnets. But now lets assume that 1 out of every 100 attempts will still be successful in by-passing the anti-virus software, and now this user is infected again.

This comfort and confidence is the problem - if this user had learned the basics about how malware works and is spread, and been educated on the simple day-to-day activities which put them at risk, I would argue that at some point, this knowledge would be more effective at stopping the infection than the anti-virus software.

So does anti-virus software make us less secure? Not really, it's the false sense of security it invokes and confidence in these solutions to make us 100% secure that make us less secure.

My recommendation for the majority of Internet users is to gain and maintain awareness of activities that make us susceptible to abuse, and as part of this education learn what anti-virus is good at, and use it for these purposes.

So Apple - Cudos on providing an operating system which reduces the ability for our computers to become infected, and reduce our reliance on anti-virus solutions, but I think more could be done to educate your customers on responsible secure Internet use.
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