stegoPromedium

Unsettled Huffman

volgactf

Task: ZIP archive with deflate-compressed PNG that is larger after compression; challenge hints at Huffman/deflate. Solution: parse raw deflate bitstream, extract block type (stored=1, fixed Huffman=0) from each of 435 blocks, decode bits as ASCII to recover the flag.

steganography zip png huffman compression deflate bitstream bait_flag

deflate_block_type_steganographyzip_internal_structure_analysisraw_bitstream_parsingbait_decoy_identification

$ ls tags/ techniques/

steganography zip png huffman compression deflate bitstream bait_flag

deflate_block_type_steganographyzip_internal_structure_analysisraw_bitstream_parsingbait_decoy_identification

Analysis

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$ python3 exploit.py --target 192.168.1.1 --port 8080
[*] Connecting to target...
[+] Shell obtained!

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