Green

Category

Cryptography

Description

I’m green da ba dee da ba dah

Solution

Attached is an image only containing a bunch of green pixels.

Using zsteg on the file we can find some interesting text.

zsteg -l 0 6e7ee269ddfdddc28304a10b36991812.png -a
b8,g,lsb,xy         .. text: "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"

After base32 decoding the string and the subsequent results seven times we get the flag.

flag{d075_4nd_d0ts}

n00bz

Home of the n00bz CTF team.


By n00bz, 2022-02-20