Off_Topic: Are there OSX viruses?

[khyber courchesne]

Hello, I just wanted to ask if there are indeed OSX viruses.  I thought
there were none, yet we have Virex sitting over there in the corner.  Just
wanted to settle a running discussion with the people in my graphics
department:  every time something goes wrong with a machine (kernel panic,
slow file transfer, etc) somebody invariably says, "it must be a virus!"
while everyone else nods in sympathy.

I know I could have posted this on lots of other more pertinent discussion
boards, but the Ti list seems to me to have the best ratio of ACTUAL expert
knowledge / probability of flame war.
Thanks people!