I've been giving this problem some thought, and did some experimenting. If you set a file to read-only permissions (chmod 444 file.ext), and set it to an owner other than your own userid (e.g., root), that file cannot be deleted or written to from a Windows box via SMB, no matter the share settings. I tested with the DOS/Windows "attrib -R" command, and it was unable to make the file writable (if the owner is me, attrib WOULD make the file writable). I believe that no virus operating through SMP