Linux - Virus free??

I have heard many people asking about viruses for Linux systems. So, is Linux really virus free? The answer is NO, it is not. But yes, there are many technical as well as other challenges in creating a malicious software for Linux. This applies for Unix systems as well. So, what are they? Lets start with the non-Technical problems.

1. Linux is opensource - One very straight forward reason is, no one is interested in opening an already open box. Its always wonderful and motivating to break through a closed system.

2. Huge Community support - This means that there are millions of developer scanning the code for any security risks. And as soon as a virus appears on the web, these developers are always ready to squash them out by providing fixes to the code. This happens much before the virus spreads to the masses. This is highly demotivating for the people who write viruses, just to get them thrown out within minutes.

2. No monetary gain for Linux viruses - Since Linux is free and created by community, there is no one who is going to pay you for writing viruses for Linux.

Now the Technical Challenges - The only technical challenge is the strict file permissioning system in the *nix based systems including Mac OS X. If you are running as root, then its as vulnerable as any other Microsoft OS. In such cases the processes will all the access they want and can easily modify the system binaries and insert virus code in them. However, if you are running as normal user, then no virus can harm your system. The processes wont have access to modify the binaries, and in any case they will not be able to change them.

Hope that was helpful. Comments invited.