Fc2-ppv-1864525: _verified_

sox audio.wav slice.wav trim 8 2 Open slice.wav in Audacity → “Plot Spectrum” → note the regular on/off bursts.

00000000 66 6c 61 67 7b 46 43 32 5f 50 50 56 5f 31 38 36 |flag4525_fake......| ... fc2-ppv-1864525

dd if=fc2_1864525.mp4 of=payload.bin bs=1 skip=124567890 strings payload.bin | grep -i flag # => flagFC2_PPV_1864525_fake Flag: sox audio

# Get the offset of the final `moov` atom (e.g. 124,567,890) tail -c +124567891 fc2_1864525.mp4 > trailing.bin hexdump -C trailing.bin | head The dump shows plain ASCII: 124,567,890) tail -c +124567891 fc2_1864525

But let’s assume the real challenge hides it deeper (e.g., the trailing data is just a decoy). We’ll keep digging to illustrate a full methodology. Even though we already located a flag, extracting the raw streams is useful for later analysis.

Using an online Morse decoder (or the morse Python library):