Audio steganography checklist

  1. Use exiftool
  2. Use strings
  3. Use Audacity and check spectrogram. Additional settings
  4. Change spectrogram to logarithmic scale
  5. Change sampling frequency
  6. Check for DTMF tones
  7. Try QSSTV
  8. Check for LSB encryptions
import wave
import struct
wav = wave.open("audio.wav", mode='rb')
frame_bytes = bytearray(list(wav.readframes(wav.getnframes())))
shorts = struct.unpack('H'*(len(frame_bytes)//2), frame_bytes)
# Extract left and right audio streams
extracted_left = shorts[::2] 
extracted_right = shorts[1::2]
extractedLSB = ""
for i in range(0, len(extracted_left)):
    extractedLSB += (str(extracted_left[i] & 1)) if (i%2)==1 else (str(extracted_right[i] & 1))

string_blocks = (extractedLSB[i:i+8] for i in range(0, len(extractedLSB), 8))
decoded = ''.join(chr(int(char, 2)) for char in string_blocks)
print(decoded[:500])
# Search in decoded text
if "ctf" in decoded.lower():
 print("YES")
else:
 print("NO")
wav.close()
  1. LSB
  2. wav-steg