CyberChef IV

This was originally a set of walkthrough challenges I created for StoutCTF 2025. They have been re-uploaded here as guides after the fact. CyberChef VIII - CyberChef X are considered to be writeups, and are in the writeups category.

CyberChef VIII: http://slavetomints.com/posts/stoutctf-cyber-chef-viii/ CyberChef IX: http://slavetomints.com/posts/stoutctf-cyber-chef-ix/ CyberChef X: http://slavetomints.com/posts/stoutctf-cyber-chef-x/

Can you decode this ciphertext?

4e544d314e44526d4e5455314e44517a4e5451304e6a64694e47553059544d304e6a6b334d5459334e7a59334d444d784e6a6b30595459314e444d304e6a5a694e6a6b324e5452694e4463325a4451304e7a41324e7a4d794d7a41334f5455344e6a45314f544d774e5455305a44646b

Walkthrough

Welcome back to the CyberChef Walkthroughs! Here we are going to go through the basics of CyberChef, with a few extra challenges at the end for you to work on.

This time, we are going to be super duper lazy, and solve the entire challenge using a single block!

I know, I know, its a lot to ask, but trust me its possible. We’re going to learn about the Magic block this time.

The Magic block has four main components to it: Depth, Intensive Mode, Extensive Language Support, and Crib.

Depth

Depth allows you to specify how “deep” or how many layers of encoding might be on the cipher text. For example, the cipher text in CyberChef II had 2 layers of encoding.

Intensive Mode

Intensive mode makes the Magic block try more complex combinations than it normally would. Be careful, this can crash the application depending on the ciphertext.

Extensive language Support

This is a mode you might not regularly use. This let’s CyberChef know you want it to check against all languages, not just the most common ones.

Crib

This tells CyberChef what the start of the plaintext is, so it can only show you ones that contain the crib in it.

Now that you’ve learned all about Magic, you can try and solve this challenge.

FLAG: STOUTCTF{NJ4iqgvp1iJeCFkieKGmDpg20yXaY0UM}