F5隐写工具：https://github.com/matthewgao/F5-steganography
$java Extract F5.jpg
Picked up _JAVA_OPTIONS: -Dawt.useSystemAAFontSettings=on -Dswing.aatext=true
Huffman decoding starts
Permutation starts
309504 indices shuffled
Extraction starts
Length of embedded file: 190 bytes
(1, 31, 5) code used
$binwalk output.txt
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
0 0x0 Zip archive data, at least v2.0 to extract, compressed size: 40, uncompressed size: 38, name: flag.txt
168 0xA8 End of Zip archive, footer length: 22
$binwalk -e output.txt
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
0 0x0 Zip archive data, at least v2.0 to extract, compressed size: 40, uncompressed size: 38, name: flag.txt
168 0xA8 End of Zip archive, footer length: 22
$cat _output.txt.extracted/flag.txt
flag{96efd0a2037d06f34199e921079778ee}
