3137.mp4 -

Did you run exiftool 3137.mp4 ? Often, flags or hints are hidden in the "Comment" or "Artist" tags.

Did you find the flag by running strings 3137.mp4 | grep "CTF{" ? 4. Final Flag Flag: FLAGexample_flag_123 3137.mp4

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 . Did you run exiftool 3137

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. Mention if you used Audacity or Sonic Visualizer

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

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

Did you watch the video for flashing frames, QR codes, or Morse code? 3. Deep Dive & Exploitation