Flatpack-522.rar

$ display cover.png Nothing obvious appears. However, the challenge name “FlatPack” hints at “flat” data (i.e., a flat image with hidden data). Use zsteg (a popular stego tool) to search for hidden data:

$ binwalk mystery.bin Output:

$ feh _mystery.bin.extracted/00000000.png The image is a . Decode it with zbarimg : flatpack-522.rar

$ steghide extract -sf cover.png -p "" -xf hidden.txt (If steghide asks for a password, just press Enter – it’s not password protected.) $ display cover

DECIMAL HEX DESCRIPTION 0 0x0 PNG image, 256 x 256, 8-bit/color RGBA, non-interlaced Extract the PNG: 256 x 256

#!/usr/bin/env bash set -e

hidden.txt now contains: