n00bs CTF Level 10
Link: http://ctf.infosecinstitute.com/levelten.php | Points: 100 |
Useful Tools: VLC Audacity |
Tags: beginner misc |
Show Solution …
The Challenge
This amusing page presents us with a picture and a button that brings us to a WAV sound file.
After a quick look through the source code, I went over to the sound file. It’s about 1-2 seconds of high pitch squeaking noises. There is absolutely no voice discernible in the squeaking, and you would probably be certain listening to it that it’s not just a voice recording sped-up very fast. There was nothing useful in the metadata of the WAV file, but we did see cookie monster from a previous challenge again.
I threw the WAV file into Audacity, a free audio editor, and slowed it down by reducing the sample rate from 44100Hz (what the .wav file was set to) all the way down a more common setting of 8000Hz.
Amazingly, those squeaks actually do turn into an understandable (albeit still fast) voice that reads out the flag to us letter-by-letter: infosec_flagis_sound
Lessons Learned
This lesson introduced us to another new, but very versatile and useful free program called Audacity. It is a very feature-filled audio editor, allowing you to do things such as changing the sample rate (speed) of the audio. Think of it as Photoshop for sound files!