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
Downloads: super_secret.jpg
Solution
So we get an image and... it's awfully big o_o 10mb image? I used binwalk right away and there's archive inside.
└─$ la
Permissions Size User Date Modified Name
.rwxr-x--- 9.9M kali 6 Aug 13:19 super_secret.jpg
└─$ binwalk --dd='.*' ./super_secret.jpg
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
0 0x0 JPEG image data, JFIF standard 1.01
166246 0x28966 Zip archive data, at least v1.0 to extract, compressed size: 9725992, uncompressed size: 9725992, name: hidden.jpg
9892256 0x96F1A0 End of Zip archive, footer length: 22
9892370 0x96F212 End of Zip archive, footer length: 22
└─$ mv _super_secret.jpg.extracted/28966 hidden.zip
└─$ unzip hidden.zip
Archive: hidden.zip
extracting: hidden.jpg
└─$ la
Permissions Size User Date Modified Name
drwxr-xr-x - kali 6 Aug 13:25 _super_secret.jpg.extracted
.rw-r--r-- 9.7M kali 19 Apr 2022 hidden.jpg # Extracted Image, Again Really Huge
.rw-r--r-- 9.7M kali 6 Aug 13:20 hidden.zip
.rwxr-x--- 9.9M kali 6 Aug 13:19 super_secret.jpg
└─$ binwalk --dd='.*' ./hidden.jpg
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
0 0x0 JPEG image data, JFIF standard 1.01
30 0x1E TIFF image data, little-endian offset of first image directory: 8
39697 0x9B11 Zip archive data, at least v2.0 to extract, compressed size: 9686117, uncompressed size: 10611338, name: SupEr_s3CrET_AuD10.wav
9725970 0x946812 End of Zip archive, footer length: 22
└─$ mv _hidden.jpg.extracted/9B11 super_secret.zip
└─$ unzip super_secret.zip
Archive: super_secret.zip
inflating: SupEr_s3CrET_AuD10.wav I opened the wav file in Sonic Visualiser and got some garbage audio.. It feels like radio audio? Combined with title I found QSSTV tool and a really interesting tutorial.
Ham Radio and Linux - Using QSSTV to decode from captured audio files
Turns out the wav file is from space! This is how astronauts send pictures (or messages).
Setup QSSTV and use it to decode the wav.
Using online QR Decoder we get the flag.
Flag: dsc{un5af3_sp4C3_coD3}
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