Summary

Author: @JohnHammond#6971

Well would you listen to those notes, that must be some long phone number or something!

Steps

In this challenge I was given a file called dialtone.wav. Listening, I hear the audible dial pad when dialing a phone number. After some research, I discoverd a github respository by ribt that will convert a .wav file dial press and correlate this with the actual number being dialed. I executed ./dtmf.py ~/huntress/dialtone.wav and received the below response.

13040004482820197714705083053746380382743933853520408575731743622366387462228661894777288573

I spent a bit of time trying to figure this value including going through the various operations on CyberChef. Eventually, I discovered Dencode. This website will encode and decode a string in various formats. With trial and error I discovered the website performed a Num to Hex encoding and gave me this string: 666c61677b36633733336566303962633466326134333133666636333038376532356436377d. Moving back to CyberChef, I decoded this value from Hex and got the flag! flag: flag{6c733ef09bc4f2a4313ff63087e25d67}