Probably the Underhanded C Contest (https://www.underhanded-c.org/_page_id_17.html) but yeah. Obfuscated C Contest entries usually aren't underhanded, just intentionally obscure about what they do or how they do it.

sorry, yes, that one.

Great contest. And a great entry, I had a big chuckle running it and unredacting my documents, even photos!