# A Monster Issue:Steg / Forensics:100ptsAgent,  We've got a case of industrial espionage, quite an unusual one at that.An international building contractor - Hamilton-Lowe, has written to usthat they are having their private client contracts leaked.  After conducting initial incident response, they managed to find a hiddendirectory on one of their public facing web-servers. However, the strangething is, instead of having any sensitive documents, it was full of mp3 musicfiles.  This is a serious affair as Hamilton-Lowe constructs facilities for high-profileclients such as the military, which means having building schematics leaked fromthem could lead to a lapse in national security.  We have attached one of these mp3 files, can you examine it and see if thereis any hidden information inside?  [aero_chord.mp3](aero_chord.mp3)  
# Solutionaero_chord.mp3を開いてみても、曲が流れるだけである。  洋楽は知らないのでbinwalkしてみる。  ```bash$ binwalk -e aero_chord.mp3
DECIMAL       HEXADECIMAL     DESCRIPTION--------------------------------------------------------------------------------1726          0x6BE           JPEG image data, JFIF standard 1.015162942       0x4EC7BE        Zip archive data, at least v2.0 to extract, uncompressed size: 191624, name: OwO.wav5252619       0x50260B        End of Zip archive
$ cd _aero_chord.mp3.extracted/_aero_chord.mp3.extracted$ ls4EC7BE.zip  OwO.wav```4EC7BE.zip(OwO.wav)とOwO.wavが得られたが進歩がない。  OwO.wavをもう一度binwalkする。  ```bash_aero_chord.mp3.extracted$ binwalk -e OwO.wav
DECIMAL       HEXADECIMAL     DESCRIPTION--------------------------------------------------------------------------------179972        0x2BF04         Zip archive data, encrypted compressed size: 11480, uncompressed size: 11854, name: flag.png191602        0x2EC72         End of Zip archive
_aero_chord.mp3.extracted$ cd _OwO.wav.extracted/_aero_chord.mp3.extracted/_OwO.wav.extracted$ ls2BF04.zip  flag.png```2BF04.zip(flag.png)はパスワードがかかっており、flag.pngは破損している。  OwO.wavに立ち返り、スぺクトログラムを見てやるとパスワードが書かれていた。  ![pass.png](images/pass.png)  Password(Shad0ws)なのでShad0wsで解凍するとflag.pngが得られた。![flag.png](images/flag.png)  
## ractf{M0nst3rcat_In5tin3t}