Pragyan 2020 - Up can be Down

Posted on mer. 26 février 2020 in CTF

Solved by: 22%

First solvers: x0r19x91
Mr. Robot is being sent to future. But accidently he lost his passkey which he needs to activate the Time Machine. But he is smart and had already asked Elliot to save the key inside a file to use it in such conditions but safely so that others can't retrieve it easily. Can you help Mr. Robot to find the secret passkey from the file?

Open ME!!!

Like usual, we can take a look to the meta-data from the image:

$ exiftool mrRobot.jpg
[...]
Format                          : U29tZSBTSEEgbWF5YmUhISEh
Comment                         : c82358dfb202ce9cfddc34e13d403fa3
Image Width                     : 2560
[...]

Hum, a strange comment inside. We can use crackstation to get the clear text if the hash is a know one. The website gave us a result:

c82358dfb202ce9cfddc34e13d403fa3 sha256 avium

We can now use this clear work to extract some hidden informations from the file:

$ steghide extract -sf mrRobot.jpg           
Enter passphrase: 
wrote extracted data to "flag.txt".
$ cat flag.txt             
Congrats! This was way too wasy :P

This is the key:

p_ctf{s0rry_6ut_1_@m_n0t_@_r060t}