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 .
Use file 3137.mp4 to confirm it is actually an MP4 and not a renamed archive or polyglot file. 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: If you found something in a single frame,
A quick summary of the trick (e.g., "The flag was hidden in the LSB of the audio channel"). such as ExifTool
Did you watch the video for flashing frames, QR codes, or Morse code? 3. Deep Dive & Exploitation