Use file 3137.mp4 to confirm it is actually an MP4 and not a renamed archive or polyglot file.
A quick summary of the trick (e.g., "The flag was hidden in the LSB of the audio channel"). 3137.mp4
List your toolkit, such as ExifTool , FFmpeg , StegSolve , Sonic Visualizer , or Strings . 2. Initial Analysis Describe your first steps after receiving the file: Use file 3137
This is the core of your write-up. Explain the "Aha!" moment: such as ExifTool
net/threads/pishem-ctf-writeup-pravil-no-zachem-eto-nuzhno-i-kak-pomogayet-razvitiyu.92117/">Codeby ?
Briefly state what the goal was (e.g., "Find the hidden flag within the video file").