Originally Posted by Wikiwide

It depends on malware writers. As long as Linux is rarely used, most malware writers don't bother to write malware for it (different flavours of Linux have different package formats, filesystems, directory structures, ways to protect against malware, Internet browsers, window managers). But if there is one particular kind of Linux which is more predictable, easier to attack and giving greater advantage, it <strike>might</strike> will be attacked.

http://en.wikipedia.org/wiki/L10n_worm
http://en.wikipedia.org/wiki/Linux_malware