UNIX for Dummies Questions & Answers

Hi,

I am becoming very curious as to why viruses attach only Windows system and not any UNIX and Linux.

Does that has to do something with the architecture or something else.

Now, I will be careful as to avoid any "political" discussion about the two OS's here, but in my mind there are two main reasons for this.

The first reason is the fact that most home PC users (and thus a large proportion of the globe's computers) run some version of Windows - therefore, for maximum impact and publicity, people attack this OS.

The second reason centres around security - for one thing, most Windows users and Sys Admins charge around as "Administrator" all day long - if they contract a virus, this can wreak havoc as the administrative user that executed it. In the *nix world, any knowledgable user (and any Sysadmin worth their salt) will operate as a normal limited user, only suing to root as and when required - so any malicious code executed will have a very limited effect on the system - if permissions and security are tight, the worst that will happen is any files in your home directory will be destroyed. Obviously, UNIX security must be implemented and maintained to be effective, so much so that whole books have been written about it.

Cheers
ZB

Yes, it has a lot to do with the architecture. Many viruses are transmitted because of the "closeness" between the Windows user interface and the operating system, Visual Basic exploits, etc, which are used by virus writers.

Another reason is that UNIX has a much better handle on security than Windows OS's do. A unix box can be locked down fairly easily and prevent most of the methods used to attack windows boxes.

So unix boxes dont make attractive targets.

Zazzy if this is the case of not using super user, have you ever seen any virus attack on UNIX systems.
I haven't in my short span of a year.

I think it has to do something with the execution of the files.
Is it so?

The only feasible way I have heard is thru internet-facing boxes which run Xwindows and use web access...via DNS attacks or overflow attacks.

Outside of that it is pretty hard to do imho...

UNIX systems are not necessarily imune, they just aren't exploited like Windows systems. Set UID as well as buffer overrun vulnerabilities have been identified on UNIX systems from time to time for all sorts of applications including Oracle 9i, which was touted as unbreakable/unhackable. Who remembers the Morris worm that exploited sendmail and crahsed countless systems accross the net more than a decade ago? This attack was the first one that caught the world's attention due to its substantial impact. CERT has advised that yet another vulnerability exists in sendmail (albeit through unauthorized distrobutions) can be compromised even through a firewall.

Thomas