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Winja CTF Writeup

Cryptography

Esoteric

Flag: flag{es2o@t$e4r&i#c_code-most_difficult_to_program}

We were given with the text 

D'`A^?]nIYXWE16Tvus1NpL-KlIH"hgDB{SRba=<)sxqYonsrqj0hPlkdcb(`Hd]#a`_A@VzZY;Qu87MqQP2HlLEiCHG@EDCBA:^!=6543Wx654-Q1qpM'&+*#G'&}|#z@~}_uts9ZYutslqpi/mlNMiha'_d]ba`_^W{[TYXWVOTSLp32HGLKDhBAF?>b%A:?87[543870T.-2+0)Mnm+$H(hg%${zy?}_{t:rq7otmrkj0ngledc)JIedcb[!B^]\UyYXWVU7Mqp3INMLEJCgGFE'=<A@?8\<;4z2V6/4-Q10po'&%I)('g%|{"!x>|{zsxwp6tmrqpi/POkjib(fe^F\"`Y^W{>=YXQu8TMLQPOHlLEJCBAeEDC<;:?8\<;{z8765.R2r*)(L9

I recognized it is malbolge esolang because I have seen this in some other CTFs. So I ran it in an online interpreter for malbolge and got the flag.

Steganography

Believe Your Eyes

Flag: flag{849d97fa58871dad45e81027f861739_maYB3_i_SHOULd_BELIeve-7HeM}

In the site for the challenge, I found this image: Image for the challenge

So I ran some basic tools like strings and exiftool. When I inspected results got from the exiftool I found the flag in the layers like flag{849d97fa58871dad4, _SHOULd_BELIeve-7HeM}, 5e81027f861739_maYB3_i. But, they weren't in order so I reordered them and found the flag.

Hardy

Flag: flag{Di77icu8tyI9now@!!#-Youdidit!!}

Encoded text given with the challenge

This one was not so hard. It was just ciphers inside ciphers. Here is the order of the ciphers:

  1. Base58
  2. Morse Code
  3. Binary
  4. Decimal to ASCII

And here is the process in cyberchef.

Forensics

Anonymous

Flag: flag{LJryyYW8IbxuZrOcZ4nd-this-is-a-challenge}

In this challenge, you will get a zip file with someone's desktop files inside. So first i tried to find any suspicious files in the folders of the user crazy_crocodile. So first I checked what files are there in the common directories like Picture/, Documents/, Music/, Downloads/, etc. But there wasn't any files in any of those directories. Then I tried to list all of the hidden directories and found .config/ directory which contained configuration files for google chrome. So I tried to look for any useful files there and I found the History file in the Defaults/ folder in the google chrome folder. So I tried cat History and found a google docs link. I tried visiting the link and tried to submit the title of the file wrapped with flag{} as the flag and it was right!

Web

b74ass

Flag: flag{D@i7s#o89!0@v&e@_php_master}

I poked around the website for some times and found that if we supply ?debug in the URL, we would get the source code of the project. And there I found that we need to make the variable final_string to roseytherehappy in order to get the flag. But, the PHP code removes every occurrence of roseytherehappy with function preg_replace. So how do we solve it? Well, the preg_replace replaces exact word with nothing. So we could insert a roseytherehappy inside any of the letters in the roseytherehappy and it will replace it, and we will get the roseytherehappy as value. So the payload will look like roseytherehapproseytherehappyy. And the final URL will look like: https://jerry.winja.site/?value=roseytherehapproseytherehappyy

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