The challenge relies on steganography or a hidden IDAT chunk tweak.

Saving and reopening the image reveals a hidden string or a URL at the very bottom of the extended canvas. 4. Decoding the Final Payload Depending on the specific version of this challenge:

Binwalk usually reveals trailing data or a zlib compressed stream that doesn't belong to the image's main structure. 2. Steganographic Discovery

XCTF{d3j4_vu_st3g0_m4st3r} (or similar depending on the event year).

Use the StegSolve.jar tool to browse through different color planes.