Winja CTF 2020: Write-up

Raj Upadhyay
InfoSec Write-ups
Published in
4 min readSep 19, 2020

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Today I participated in Winja CTF, It was a really Awesome Experience.

I was able to solve 7 challenges so here I am sharing my approach to solve them.

1. Liar Liar

The first thing I did was check “file” command itself.

file

So it’s ASCII text file.

so I tried cat this_is_a_binary

cat file

So in img src, we can see we have one base64 string. So next thing I did was decode it using base64

base64

So we got HEX value.

so next thing i did was “HEX to ASCII”

hex to ascii

Flag : flag{8su3nsh_HONESTY_is_the_Best_Policy}

2. ZIP BOMB

So I download attachment,

So it was a zip file so I extracted it one by one while extracting the 2nd zip file we need to give a password so I guessed the password “pass123” and my guessing was right. else I will do zip password cracking online using “ilostmypass.com”

The next step is to open flag.txt file

Flag : flag{n0t_as_g0od_as_middl3_0u1_righ1}

3. F@#$ YOUR MIND

we have been given one txt file. it looks like this

At first look, I know this is javascript obfuscator code ( As you play more CTF you can surly predict things by just looking them)

So I used “https://lelinhtinh.github.io/de4js/” to deobfuscate.

In challenge they told us to put string in “flag{}”

Flag:

flag {cr@zy-e50t3r1c-l@ngu@g3_ejsSoOM7bh_MyNameIsDrLeamas}

4. Attack.log

we have been given one pcap file.

The first thing I did was exported all the files. (Export HTTP object list)

So as we can see we have 3 files. one “Linux-virus” file and two HTML files

So I tried strings on linux-virus file.

In the above image, you can see I have highlighted some Hash values,

At first look, it was strange to see HASH values in strings. So I tried to crack this HASH value via CRACKSTATION. and i was right it’s HASH value and got value “999999”

So now I opened HTML files and try to find “999999”

I found “999999” on the HTML file and I submitted a flag value.

Flag : flag{ZDBKEPXZQUECXDVJT}

5. Risk Aversion

We have been given one exe file.

So first thing i did was “File” command on exe

So we can see it’s not an exe file it’s ASCII text file.

So next thing I did was “cat format-c.exe”

Flag: flag{QKHek1Oblm_MrGrinnyWouldLikeToCongratulateYou}

6. Trader’s Gambit 1

trader’s Gambit 1

So firstly I visited this website

bank.site

So looked at different things “source code”,”javascript file”,”css” etc.

After then I thought let me try different URLs like “/admin,/login,/robots.txt”.

After a while, I tried “/flags” and I got 2 flags.

flags

So the First flag was for this challenge.

Flag : flag{YouFoundKorla_SqlInjectionSuccessful}

7. Trader’s Gambit 2

So when I saw the URL, it’s was the same URL so in previous challenge we found 2 flags so the 2nd flag was for this challenge.

flag : flag{LimitBypassed_IVFfxMQQwb_ThisAccountBelongsToKorla}

Thank you for reading.

You can find all resources at the link below.

https://github.com/raj1997/CTF-Write-up/tree/master/Winja_CTF

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Pursuing M. Tech. in Cyber Security and Incident Response. #LoveToPlayCTF #infosec #cybersecurity