TYPE: FORENSICS | DIFFICULTY: hard |BY: Deer
ctflearn challenge page :https://ctflearn.com/challenge/441
in this CTF we have a zip file(massege.zip) so we will unzip it using unzip
unzip massage.zip
we found a file inside the folder and that’s or target , we have to analyz the help.me file
let’s start with the basics ,use file to know more about our target
file help.me
as we can see her the file is an audio file let’s use another tool to make sure
use exiftool to know more detail about help.me file
exiftool help.me
Yes ! It’s an audio
now we are sure that it’s an audio file So we will change the extension of the help.me file to help.ogg — rename the file
after listening to the audio in (audacity) you can hear nothing but some disturbance so lets analyze the audio file using audacity or sonic-visualiser
for me audacity wasn't helpful but it may work for you , i used sonic-visualiser
sonic-visualiser help.ogg
lets check if there is any spectrogram in this audio file , press layer in the top bar then Add Spectogram and her is the surprise!
yesss! just scan the QR code and you will get the flag!! easy busy
