Audio Steganography

Tip

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์ผ๋ฐ˜์ ์ธ ํŒจํ„ด:

  • Spectrogram messages
  • WAV LSB embedding
  • DTMF / dial tones encoding
  • Metadata payloads

๋น ๋ฅธ ์ ๊ฒ€

ํŠน์ˆ˜ ํˆด์„ ์‚ฌ์šฉํ•˜๊ธฐ ์ „์—:

  • ์ฝ”๋ฑ/์ปจํ…Œ์ด๋„ˆ ์„ธ๋ถ€์ •๋ณด ๋ฐ ์ด์ƒ ์—ฌ๋ถ€ ํ™•์ธ:
  • file audio
  • ffmpeg -v info -i audio -f null -
  • ์˜ค๋””์˜ค์— ์žก์Œ ๊ฐ™์€ ๋‚ด์šฉ์ด๋‚˜ ํ†ค ๊ตฌ์กฐ๊ฐ€ ํฌํ•จ๋˜์–ด ์žˆ๋‹ค๋ฉด, ์ดˆ๊ธฐ์— spectrogram์„ ํ™•์ธํ•˜์„ธ์š”.
ffmpeg -v info -i stego.mp3 -f null -

Spectrogram steganography

Technique

Spectrogram stego๋Š” ์‹œ๊ฐ„/์ฃผํŒŒ์ˆ˜์— ๋”ฐ๋ผ ์—๋„ˆ์ง€๋ฅผ ์กฐํ˜•ํ•˜์—ฌ ๋ฐ์ดํ„ฐ๋ฅผ ์ˆจ๊น๋‹ˆ๋‹ค. ์ด๋ ‡๊ฒŒ ํ•˜๋ฉด ์‹œ๊ฐ„-์ฃผํŒŒ์ˆ˜ ํ”Œ๋กฏ์—์„œ๋งŒ ๋ณด์ด๊ฒŒ ๋˜๋ฉฐ(์ข…์ข… ๋“ค๋ฆฌ์ง€ ์•Š๊ฑฐ๋‚˜ ๋…ธ์ด์ฆˆ๋กœ ์ธ์‹๋ฉ๋‹ˆ๋‹ค).

Sonic Visualiser

์ŠคํŽ™ํŠธ๋กœ๊ทธ๋žจ ๊ฒ€์‚ฌ์šฉ ์ฃผ์š” ๋„๊ตฌ:

Alternatives

  • Audacity (์ŠคํŽ™ํŠธ๋กœ๊ทธ๋žจ ๋ณด๊ธฐ, ํ•„ํ„ฐ): https://www.audacityteam.org/
  • sox๋Š” CLI์—์„œ ์ŠคํŽ™ํŠธ๋กœ๊ทธ๋žจ์„ ์ƒ์„ฑํ•  ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค:
sox input.wav -n spectrogram -o spectrogram.png

FSK / modem decoding

Frequency-shift keyed audio๋Š” ์ข…์ข… ์ŠคํŽ™ํŠธ๋กœ๊ทธ๋žจ์—์„œ ๋ฒˆ๊ฐˆ์•„ ๋‚˜ํƒ€๋‚˜๋Š” ๋‹จ์ผ ํ†ค์ฒ˜๋Ÿผ ๋ณด์ž…๋‹ˆ๋‹ค. ๋Œ€๋žต์ ์ธ center/shift ๋ฐ baud ์ถ”์ •์น˜๋ฅผ ์–ป์—ˆ์œผ๋ฉด, minimodem์œผ๋กœ brute force ํ•˜์„ธ์š”:

# Visualize the band to pick baud/frequency
sox noise.wav -n spectrogram -o spec.png

# Try common bauds until printable text appears
minimodem -f noise.wav 45
minimodem -f noise.wav 300
minimodem -f noise.wav 1200
minimodem -f noise.wav 2400

minimodem์€ mark/space tones์— ๋Œ€ํ•ด ์ž๋™ ๊ฒŒ์ธ ๋ฐ ์ž๋™ ๊ฐ์ง€๋ฅผ ์ˆ˜ํ–‰ํ•ฉ๋‹ˆ๋‹ค; ์ถœ๋ ฅ์ด ๊นจ์ง€๋ฉด --rx-invert ๋˜๋Š” --samplerate๋ฅผ ์กฐ์ •ํ•˜์„ธ์š”.

WAV LSB

๊ธฐ๋ฒ•

๋ฌด์••์ถ• PCM (WAV)์˜ ๊ฒฝ์šฐ, ๊ฐ ์ƒ˜ํ”Œ์€ ์ •์ˆ˜์ž…๋‹ˆ๋‹ค. ํ•˜์œ„ ๋น„ํŠธ๋ฅผ ์ˆ˜์ •ํ•˜๋ฉด ํŒŒํ˜•์ด ์•„์ฃผ ์•ฝ๊ฐ„ ๋ณ€ํ•˜๋ฏ€๋กœ ๊ณต๊ฒฉ์ž๋Š” ๋‹ค์Œ์„ ์ˆจ๊ธธ ์ˆ˜ ์žˆ์Šต๋‹ˆ๋‹ค:

  • ์ƒ˜ํ”Œ๋‹น 1๋น„ํŠธ(๋˜๋Š” ๊ทธ ์ด์ƒ)
  • ์ฑ„๋„์— ์ธํ„ฐ๋ฆฌ๋ธŒ๋จ
  • ์ŠคํŠธ๋ผ์ด๋“œ/์ˆœ์—ด ์‚ฌ์šฉ

๋งŒ๋‚  ์ˆ˜ ์žˆ๋Š” ๋‹ค๋ฅธ ์˜ค๋””์˜ค ์€๋‹‰ ๋ฐฉ์‹:

  • Phase coding
  • Echo hiding
  • Spread-spectrum embedding
  • Codec-side channels (ํฌ๋งท ์˜์กด์  ๋ฐ ๋„๊ตฌ ์˜์กด์ )

WavSteg

From: https://github.com/ragibson/Steganography#WavSteg

python3 WavSteg.py -r -b 1 -s sound.wav -o out.bin
python3 WavSteg.py -r -b 2 -s sound.wav -o out.bin

DeepSound

DTMF / ๋‹ค์ด์–ผ ํ†ค

๊ธฐ๋ฒ•

DTMF๋Š” ๋ฌธ์ž๋ฅผ ๊ณ ์ •๋œ ๋‘ ์ฃผํŒŒ์ˆ˜ ์Œ์œผ๋กœ ์ธ์ฝ”๋”ฉํ•ฉ๋‹ˆ๋‹ค(telephone keypad). ์˜ค๋””์˜ค๊ฐ€ ํ‚คํŒจ๋“œ ํ†ค์ด๋‚˜ ๊ทœ์น™์ ์ธ ์ด์ค‘ ์ฃผํŒŒ์ˆ˜ ๋น„ํ”„์Œ๊ณผ ์œ ์‚ฌํ•˜๋‹ค๋ฉด, DTMF ๋””์ฝ”๋”ฉ์„ ์กฐ๊ธฐ์— ํ…Œ์ŠคํŠธํ•˜์„ธ์š”.

์˜จ๋ผ์ธ ๋””์ฝ”๋”:

์ฐธ๊ณ ์ž๋ฃŒ

Tip

AWS ํ•ดํ‚น ๋ฐฐ์šฐ๊ธฐ ๋ฐ ์—ฐ์Šตํ•˜๊ธฐ:HackTricks Training AWS Red Team Expert (ARTE)
GCP ํ•ดํ‚น ๋ฐฐ์šฐ๊ธฐ ๋ฐ ์—ฐ์Šตํ•˜๊ธฐ: HackTricks Training GCP Red Team Expert (GRTE) Azure ํ•ดํ‚น ๋ฐฐ์šฐ๊ธฐ ๋ฐ ์—ฐ์Šตํ•˜๊ธฐ: HackTricks Training Azure Red Team Expert (AzRTE)

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