Originally Posted by MoodyBlues
How does NT compare to *nix in terms of its inherent security, vis-à-vis its file system, permissions, user privileges, etc.?
I'm not the expert. But I'm sure it's mostly file-system permissions and user privileges. In *NIX OSs the system wont try to run something if it isn't marked as "executable". You would never mark a JPG as "executable", so the system wouldn't try to run it. So even if there was malicious code inside a JPG, it wouldn't run.
Windows on the other hand, everything is executable, EXE, BMP, GIF, JPG, MP3, WAV, DOC, PPT, etc. This is why you get malicious BMPs, GIFs, MP3s, DOCs, that have code inside them, which can be executed by say a buffer-overflow vulnerability(code injection). And if the system is running as admin or root, as Windows does by default, it's pwned, as they say.