PerlBot: A reason to run anti-virus on Linux?

This morning I noticed that SANS were talking about a Perl bot that has been reported on various Unix systems. I went looking for this file and noticed that a colleague had already updated the identity for Mal/PerlBot-A to detect it.

SophosLabs see large numbers of malware affecting Windows everyday and while malware affecting other operating system is rarer no operating system is immune (Mac).

SophosLabs recommends that all computer users use anti-virus even those running *nixes.