That doesn't actually say anything about this blackjack... Check out this "What is network blackjack on port 1025" page. It's a page cached by Google since it gave me a "Forbidden" message when I tried to enter the actual page.
And about closing that port, you should get a firewall. See The FAQ.
Q: Why do computer scientists confuse Christmas and Halloween?
A: Because Oct 31 = Dec 25