3137.mp4

Briefly state what the goal was (e.g., "Find the hidden flag within the video file").

If the video looked normal, did you check the audio track? Mention if you used Audacity or Sonic Visualizer to look at the Spectrogram for hidden text. 3137.mp4

A quick summary of the trick (e.g., "The flag was hidden in the LSB of the audio channel"). Briefly state what the goal was (e

Did you find the flag by running strings 3137.mp4 | grep "CTF{" ? 4. Final Flag Flag: FLAGexample_flag_123 A quick summary of the trick (e

Use file 3137.mp4 to confirm it is actually an MP4 and not a renamed archive or polyglot file.

If you found something in a single frame, explain how you extracted it using ffmpeg -i 3137.mp4 -vf "select=eq(n\,3137)" -vframes 1 out.png .

List your toolkit, such as ExifTool , FFmpeg , StegSolve , Sonic Visualizer , or Strings . 2. Initial Analysis Describe your first steps after receiving the file: