DeconstruCTF 2023 - Missing

Description

Jason todd went missing and all alfred was able to recover from his pc was this file
Help Alfred find Jason

Author: Rakhul

Downloads: jason.rar

Solution

└─$ unrar x jason.rar
Enter password (will not be echoed) for cryptic-tod-secure/.git/config: 

└─$ rar2john jason.rar > jason.hash

└─$ john jason.hash --wordlist=$rockyou
...
jason.rar:1983
...

I couldn’t extract with unrar, so I just drag and dropped from GUI with cracked password.

└─$ la
Permissions Size User Date Modified Name
drwxr-xr-x     - kali  1 Jun  2022   cryptic-tod-secure
.rwxr-x---   44k kali  6 Aug 20:32   jason.rar
drwxr-xr-x     - kali  1 Jun  2022   nothing_here_to_look_at

First I decided to look inside nothing_here_to_look_at (because of the name).

└─$ la ./nothing_here_to_look_at 
Permissions Size User Date Modified Name
drwxr-xr-x     - kali  6 Aug 20:50   .git
.rw-r--r--   180 kali  1 Jun  2022   empty.txt
.rw-r--r--    90 kali  1 Jun  2022   encoded.txt
.rw-r--r--   805 kali  1 Jun  2022   secret.txt

# Above files had nothing interesting so I decided to look into git commits.

└─$ git log --oneline
65e36b3 (HEAD -> main, origin/main, origin/HEAD) Create encoded.txt
c707cc5 Create secret.txt
38daa61 Update empty.txt
f50086b something for u
                                                                       
└─$ git reset --hard f50086b
HEAD is now at f50086b something for u
                                                                                                                                                                                                                  
└─$ la                           
Permissions Size User Date Modified Name
drwxr-xr-x     - kali  6 Aug 20:52   .git
.rw-r--r--   137 kali  6 Aug 20:52   empty.txt
                                                                                                                                                                                                                  
└─$ cat empty.txt 
this link might be interesting
...
aHR0cHM6Ly93d3cuaW5zdGFncmFtLmNvbS90b2RkX2phc29uX3NlY3VyZS8=
...

└─$ echo -n 'aHR0cHM6Ly93d3cuaW5zdGFncmFtLmNvbS90b2RkX2phc29uX3NlY3VyZS8=' | base64 -d
https://www.instagram.com/todd_jason_secure/         

https://www.instagram.com/p/CeQvnKyr5uK/:

https://www.instagram.com/p/CeQvw7SrCBY/:

Twitter: https://twitter.com/toddjasonsecure

Second Post

Encoding looked like Base64, but it failed so I tried Base32 because of leading ===.

Flag: dsc{h4vINg_FuN_w17h_O5INT_@Nd_m4p5}