What’s the current state of Windows Anti-Virus?

One of our co-op’s clients asked me what I use for anti-virus at the moment and tips for what they should use on their Windows system.

Well, flame me now, but I don’t actually use any anti-virus at the moment: I rely on system security, firewalling and intrusion detection. The diversity of GNU/Linux software – and I use some pretty odd stuff – probably helps too. Even if I did want to run antivirus software, most of what’s available for GNU is actually aimed at detecting and preventing transmission of Windows viruses. There are few real-world GNU viruses and fewer attack opportunities left open.

Also, I prefer firewalling and fairly paranoid security settings because, like an antibiotic, an antivirus is only effective once the virus is already on your system somehow – hopefully held in quarantine by the browser or email client and not actively malignant in the processor.

There’s quite a list at http://en.wikipedia.org/wiki/Comparison_of_antivirus_software#Microsoft_Windows but I expect most of the purchase-free proprietary ones (labelled as “Free” or “Freemium” but you usually pay by watching adverts) will try to sell you upgrades, as that’s how their production is funded. If you don’t mind doing such things, you can disable the ads in at least one of them

The only very free ones I found were Immunet (also funded by upgrades – not sure if it’s actually Free and Open Source Software) and ClamWin (donation-funded) which both use the same scanning engine. If I had to use Microsoft Windows, I think I’d probably use and donate to ClamWin, install the (altruism-funded I think) Clam Sentinel alongside it and be rather cautious about what I downloaded or used online. I’m a bit worried that it doesn’t do great in reviews, though. What do/would you do?

I don’t really know about paying for security. The only paid product I’ve really seen has been Norton and that seemed no better than the ad-funded ones, still getting in the way and always trying to sell upgrades. It also irks me that there’s this huge market just to fix fundamental defects in Microsoft’s product. There’s a Microsoft Security Essentials add-on listed on Wikipedia, but it does fairly badly in this PC Magazine review – and do any of them do intrusion detection?

And finally, if you do decide to download something new, I strongly suggest getting it from a trusted source and/or triple-checking the link with wikipedia, a magazine review like CNET and a search engine. Don’t just trust a search engine, because fake antivirus software is a big way of getting viruses and worse onto computers: there’s even one calling itself “Microsoft Security Essentials 2011”!