[vox-tech] is Linux truely immune to virus?

[Hai Yi]

Hi, I accidentally downloaded a program down to my Ubuntu and SCPed it
to my Windows vista. I used McAfee to scan it and found it's a Trojan
and it was quarantined.

My concern is that, since I downloaded it in my Linux box in the first
place, even I removed it afterward, I am not sure that's enough. I
heard that Linux is virus-free, but I don't know how that conclusion
is drawn and under what conditions?

Thanks,
Hai