K!nd4SUS CTF 2025 - Writeup

CTFTime: https://ctftime.org/event/2703 ↗

Misc#

Otamatone my beloved#

Description

I was studying how to play the Otamatone when a stranger stole my pc. I wonder if he did anything strange with it…

download files at https://drive.google.com/file/d/1fVNWqYGt-4-zChfzo3wW9MyK5Zn765kJ/view?usp=drive_link ↗

Solve

Ok, actually, what i did for this chall is unzip the file (otamatone.zip). It has a dump.raw. It’s an uncompressed image data. Then , i just check any CLI forensic tool one by one. I tried exiftool, steghide, binwalk, and finally got the flag using strings command. It’s because we already know the flag is in KSUS{*} format. It will take a bit time because its size is 3.2 GB.

Flag

KSUS{d0_I_n33d_4n_MSc_t0_us3_v0la7ili7y?_dhx8z}

OSINT#

Hop on, hop off #1#

Description

Enjoying brunch. Flag format: KSUS{Name_Of_Brunch_Spot} Attachment : 1.png

Solve

What i did forstly is put this picture to Google Lens. Actually we can see that it is accross a restaurant named “Panda wok” in Budapest. After taht, move to Google Maps to see what is actually accross the restaurant.

We all see there is a brunch cafe named “Cafe Muse”. Just wrap it to KSUS{} format and challenge solved!

Flag

KSUS{Cafe_Muse}

Rev-Pwn#

Granny’s gift#

Description

My sweet Italian grandma made this beautiful keychain for me… She keeps saying it’s just a keychain, but I really don’t believe her! Attachment : challenge.zip

Solve

Ok, firstly, we gotta open the zip file up. After i opened it, it has 2 files (whatisthis.py adn gift.png). The whatisthis.py is a python script that has the flag we need. If you look at it more closely, you can see that it’s a simple script that prints out the flag if we know the key.

import hashlib
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad, unpad
import os
import base64

KEY = "8f149350416bf5a318c91a4072b4c44fe32ec03d5571412ab0dcfc6cb366574e"
FLAG = "3vQmUeUhdaV39wLvJf2OjwFLnUfx4KhGWcx/gyOnlX4lVIsRf6lAeQCCt7rp4fsCZ7iuVyfW09G7dbNEn8+MEuWzG1HbUTyILGzFGHUw6xo="

It looks like hash with md5 or sha256. So, i used online tool ↗ or click this https://crackstation.net/ ↗ for cracking this hash. I got “ti amo” as the key. Run the python script, then input the key, Boomm!!

Flag :

KSUS{W3_us3d_t0_s3nd_th3s3_w1th_p1g30ns_4t_my_t1m3_y0u_kn0w}

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