Tags: crypto 

Rating:

[Z3r0 C00l Bruh!]
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Question:
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Hackers keep secrets.

Answer
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1. We are presented a file with the name "hackers.jpeg"
2. After running some diagnostic on it e.g strings, we can see that there is something off with the headers of the file

![alt text](https://i.imgur.com/95Ote39.png)

4. As I've done a lot of stego my self, this is obviously used with steghide, as it presents these headers / hexinfo
5. I unlocked the hints as my bruteforce didn't go as planned in terms of extracting the embedded file
6. After i while, i thought why not try "neverlanctf" for the password of the picture
7. steghide extract -sf hackers.jpeg --passphrase neverlanct

![alt text](https://i.imgur.com/9q4TPMl.png)

8. Cat the output of the file "Ohno.txt" presents us with the following:

I wonder what this is????
Fowbjcsniuwcwscotsxvevvko

9. Firstly i thought it was base64 (it was not)
10. Secondly i thought it was a caesar cipher / rot 13 (it was not)
11. Thidrdly i thought it was a Viginere cipher
12. It was a Viginere with the password "hackers" (as the hint gave us "what are they")

![alt text](https://i.imgur.com/Ag2OGOh.png)

The result of the decryptet message:
Yourflagismyfavoritemovie

13. Tried first "Yourflagismyfavoritemovie"
14. Tried second "myfavoritemovie"
15. Success!

Comment:
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hint1: Most CTF keys are the name of the CTF but not all.
hint2: What Are they?

Flag:
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Yourflagismyfavoritemovie
myfavoritemovie

Original writeup (https://github.com/str0nkus/NeverlanCTF-2019-Writeups/tree/master/Crypto/Z3r0_C00l_Bruh).