Hey Lorenzo!
Thanks for the reply. By malware I meant a more general category. I would be more content to speak of viruses, which would include things attaching themselves to daemons and things which would copy your passwords and start sending out spam.
In view of the argument of the amount of users I guess one of the questions once could ask is whether Linux would have more viruses and would be a less safe environment if it begins to be used as widely as Windows.
My current answer is "no", but many people say "yes". How would you answer this question?