There’s a fair bit of reviews and comparisons of the various free anti-virus programs that are readily available. I’m not going to attempt to review them or compare their differences, just highlight and interesting ‘experiment’ that I’ve been running for a while.

I manage a number of computers – work computers, home laptop, laptops of family/friends etc. About a year or two about, I started installing different anti-virus products on each one as part of an on-going test to see what the usability of them was like.

I started doing this because I used to always use AVG on all computers I managed. I noticed that every 6-12 months or so, AVG would prompt for a full program update that would require a re-install of the new version. Less technical users found this confusing and complicated to deal with.

I started testing Avast, Microsoft Security Essentials and Avira (although less often than the others).

Yesterday, I got an interesting slice of information on this test. A work PC got infected by a backdoor trojan, compromising all data on the machine. It was running Microsoft Security Essentials.

MSE picked up the problem after it was infected, but obviously it’s real-time protection didn’t stop it from happening in the first place. In the end, we had to wipe the partition and re-install the OS to resolve the issue.

Although I didn’t do an in-depth analysis of the browsing behaviour on that PC, the operator of it confirmed they had not been on any ‘dodgy’ websites, but had viewed some sports blogs. I suspect the malware came from an embedded video ad in one of those sites, but can’t be sure.

What I can conclude is that one of the systems running MSE was compromised, most likely through fairly average browsing behaviour. Other systems running Avast with more ‘dangerous’ browsing behaviour have not been compromised.

There are obviously a lot of issues to take into account, but I think that’s an interesting observation.