Space Ahoy

DESCRIPTION

Brian tries to send some crucial information from the spacestation about an impending disaster through a super secure line to his friend through a picture. Help his friend uncover the truth .. Author: Rakhul FLAG FORMAT: dsc{[a-zA-Z0-9_]+}

Solution

  • Running strings on the given jpg file we can see there are 2 files embedded in it

    • SupEr_s3CrET_AuD10.wav

    • hidden.jpg

  • There is an interesting comment which we can get by running exiftool super_secret.jpg which says

 Comment: the aliens are here try slowscan

  • This comment will be useful later

  • We can extract the files using binwalk -e super_secret.jpg

  • We get hidden.jpg which has files embedded in it

  • Again binwalk -e hidden.jpg gives us a wav file

  • The comment comes into play here: the aliens are here try slowscan

  • On reasearching about slowscan, I came across Slow-Scan Television which is picture transmission method.

  • To decode this there is a tool called QSSTV. Check this article for installation

  • There is an alternate way to give the wav file to qsstv instead of using pavucontrol

    • Options > Configuration > Sound > Sound Input > From File

  • After setting up QSSTV and running it we get an image with a qr code on the top left

qr

  • Scanning the qr code gives us the flag

  • Flag: dsc{un5af3_sp4C3_coD3}

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