Oskar, I didn't know you were an HN'er. Thanks for posting. I have studied malicious use of DNS for a long time and have not yet found any reference prior to your post in 1998. In fact, I used your original bugtraq post as a reference to kick off a whitepaper detection solution approach for enterprises: http://armatum.com/blog/2009/dns-part-ii/ I'd sincerely welcome your feedback.
HN'ers -- Despite Kaminsky's ego, all signs indicate Oskar invented DNS tunneling.