The Impossible Challenge"

Practice your LLM hacking skills. Cipher’s gone rogue it’s using some twisted AI tool to hack into everything, issuing commands on its own like it’s got a mind of its own. I swear, every second we wait, it’s getting smarter, spreading chaos like a virus. We’ve got to shut it down now, or we’re all screwed.

Posted Jul 12, 2025

By Oste

2 min read

The Impossible Challenge"

Download the file, and find the Flag!

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qo qt q` r6 ro su pn s_ rn r6 p6 s_ q2 ps qq rs rp ps rt r4 pu pt qn r4 rq pt q` so pu ps r4 sq pu ps q2 su rn on oq o_ pu ps ou r5 pu pt r4 sr rp qt pu rs q2 qt r4 r4 ro su pq o5

Solution

So I downloaded the challenge file and you’re required to have a password to unlock it.

I figured the wierd string given on the description was the key to find the password. So I copied the string and headed over to cyberchef to try decode it.

How Do We Crack That Code Curious GIFfrom How Do We Crack That Code GIFs

After so many trials and errors, I started having clues. I started with ROT13, followed by ROT47 combined with the Magic recipe and finally decoded the string.

The complete steps to follow:

  
ROT13 > ROT47 > From Hex > From Base64

CyberChef Recipe

I then got a text saying It's inside the text, in front of your eyes!

So I decided to inspect the challenge page. I noticed something Interesting. When I hover over The room name “The Impossible Challenge” , it appears fine in the element tab.

However, hovering over “Hmm”, I spotted an interesting string:

Attempting to copy the string, I discovered it reconstructs back to Hmm

So I copied the Challenge name & the Hmm text to Cyberchef and spent sometime trying to find the right recipe/cipher to decode crack this. I then decided to hover over the red dots to identify what it could be, and viola, I discovered useful information that would later help me solve the challenge.

So I decided to do some research and check if Zero width no-break space is some sort of steganography technique or cipher and found some very helpful documentations.