http://www.computerworld.com/action/article.do?command=viewArticleBasic&taxonomyName=security&articleId=9064683&taxonomyId=17&intsrc=kc_top

From the article:
"Sophos senior security consultant Carole Theriault said Linux users can be lulled into thinking that their systems are bulletproof because malware rarely targets open-source systems.

"The number of malware in existence is around 350,000, and while only a teeny number of these target Linux, it seems as though hackers are taking advantage of this false sense of security," Theriault said."