"The list of Trojan horse ports is generated from the standard Unix Trojan list. To date, no Trojan horse applications that create TCP/IP connections have been detected on Macintosh computers but due to their popularity in the hacker community and that Mac OS X is derived from BSD Unix, it's only a matter of time.  If and when Macintosh specific Trojan horse applications are identified, this list will be replaced with a more specific list of Trojan horse ports." (Symantec)