There has been a lot of debate recently over whether or not it's a good idea to run an anti-virus program if you're using Linux. I hope to clear up a common misunderstanding: An anti-virus program running on Linux is designed to detect Windows viruses, so that they aren't spread, unknowingly, by the Linux user. This article explains when you should run a Linux anti-virus, and what exactly they do.

As long as NTFS partitions continue to sprawl over heterogeneous networks, anti-virus companies will dole out scanners for Linux. No surprise then that AVG Technologies, makers of the popular AVG Anti-Virus, has a scanner that runs on Linux in its latest 8.5 series bouquet.

And the simple answer is: no, you do not need an anti-virus in Linux. Yes, let me tell you a little secret. Come closer. That's it. You don't need an anti-virus in Windows, either! Boom! There you go.

So far, I don’t have much to say about Linux, however, the one thing I’m seriously hung up on is the lack of anti-virus. Having been a Windows user for such a long time, it’s etched in my brain that anti-virus is a must and that if you don’t have it, then you’re an idiot.

When a seasoned Windows user first migrates to Linux, the first question is always “where is the anti-virus?” I have been asked this question countless time and were always given the “you are lying to me” kind of look when I told them that they don’t need anti-virus software in Linux.

There are quite a few anti-virus packages that work with Linux, such as ClamAV, AVG, Avast!, Panda, NOD32, Avira, F-Prot, Kaspersky, eScan and Sophos. I got these names from a quick Google search and it may not be an exhaustive list. Most of those packages are proprietary, some are free and open source. Many of them charge licence fees.

If Linux is hardly affected by viruses, why do system administrators use anti-virus software on their Linux email servers? Because an anti-virus scanner on a mail server can serve as another level of defense for Microsoft Windows desktop users.

You don’t usually hear that phrase spoken “Linux anti-virus”. But it does exist. One of the more popular Linux anti-virus tools is ClamAV. But to most users (especially new users) ClamAV is a bit challenging to use. That is where KlamAV comes in.

Anti-virus companies play a losing game. Casting their nets wide, they catch common, malicious viruses and worms (known to the industry as “malware”), but it may take days before their software updates can prepare your computer for the next attack. By then it could be too late.