alt Hacker NewsI'm happy this is public domain. In 2023 I used the stain images as the basis for a CTF challenge (for BSidesSF). The encoded flag given to participants was https://github.com/BSidesSF/ctf-2023-release/blob/main/alien...
Unfortunately the challenge was a bit too hard and went unsolved during the competition.
It's hard to imagine a reason for it being kept... proprietary?