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Dame Dango

Where’s the flag?

Points: 1971 [2000]

Description

There’s plenty of space to hide flags in our spacious office. Let’s see if you can find it!

Please view this Document for download instructions.

Solution

  1. Initially I thought there are some files hidden in between the chunks of the PNG image, so I went to Wikipedia and realised that there exists tEXt and zTXt chunks within a PNG image.
  2. So I went to find a tEXt extractor online and found https://www.dcode.fr/png-chunks. I uploaded the image and it gave me a ridiculously long Base64 string. dCode
  3. Decoding the base64 reveals that it is another image based on its file signature of IPNG. Another
  4. Unfortunately, it wasn’t another zTXT or tEXt chunk, so I went online and I found this blogpost regarding StegOnline: https://medium.com/ctf-writeups/stegonline-a-new-steganography-tool-b4eddb8f8f57
  5. After noticing that the image has custom colour palettes, I went and explored some random palettes to find the flag at the bottom of the pole. Flag

Flag

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