Zip, Zip, Hooray!

broncoctf2026

Task: a mislabeled challenge.zip is actually a 1250-layer deep chain of recursively nested archives (gzip -> tar -> bzip2 -> password-protected 7z -> zip -> repeat). Solution: script 7z as a universal driver to list+extract each layer, deriving each 7z password from the first member's filename, filtering the tar @PaxHeader artifact, and recursing until flag.txt.