Home CTF Crypto Write-up | The Cyber Grabs CTF 0x02.

Crypto Write-up | The Cyber Grabs CTF 0x02.

by Nihal Umar

The Cyber Grabs CTF


Welcome to The Cyber Grabs CTF buddy :)
Flag format: cybergrabs{}
Author: Odin


Challenge file: @[email protected]@@[email protected][email protected]@[email protected][email protected]@@[email protected]@[email protected]@[email protected][email protected][email protected]@[email protected]@[email protected]@[email protected][email protected]@[email protected]@[email protected]@@@[email protected][email protected]@@[email protected]@[email protected]@[email protected][email protected][email protected][email protected]@@[email protected][email protected][email protected][email protected][email protected][email protected]@[email protected][email protected][email protected]@@@[email protected]@[email protected][email protected][email protected][email protected]@[email protected]@[email protected]@@@@@[email protected]@@@@[email protected]@[email protected]@@[email protected][email protected][email protected][email protected]@[email protected][email protected]@@[email protected]@[email protected]@[email protected][email protected][email protected][email protected][email protected][email protected][email protected]@@@@[email protected][email protected][email protected][email protected]@[email protected][email protected]@[email protected][email protected][email protected]@@[email protected]@[email protected][email protected][email protected]@@[email protected][email protected][email protected][email protected]@[email protected][email protected][email protected]@@[email protected]$

When you look at the challenge file. You will See there is same pattern follow of Encoding @ and $ So just replace @ -> 0 and $ -> 1 will give you.


and after just use any binary decoder you will get the flag.


Easiest One

Listen the audio carefully.
Flag format: cybergrabs{}
Author: Nihal


You will get .wav file in this challenge. After listening it. You will get to know that it’s in Morse code. So, use this online tool to decode it.


cybergrabs{1S TH1S A M0RS3 C0D3?}

Something feasy

Key to unlock anything is already with you.
Flag format: cybergrabs{}
Author: Odin


Challenge file:
Cipher =>  O|k.Wa{.]{|k.Wa{.[}kj.Ma||kmz.Ekw.4.P*-PP(---*(*-*(/P(((+h(N-$P$(PPhPh-P-PNh-(P*(/PoP--&-(Pj(N-*NhPo-+(&P-P&P--PP(-&(/-*P+Nl

In this challenge first you got the file. It has Encrypted text and as its description says Key to unlock anything is already with you.

So if u apply Xor decryption on it you with the key as key you can get the decrypted text like this:

Are You Sure You Used Correct Key : ^$#^^&###$&$#$&!^&&&%f&@#*^*&^^f^f#^#^@f#&^$&!^a^##(#&^d&@#[email protected]^a#%&(^#^(^##^^&#(&!#$^%@b

Hint: Remember your keyboard is your true friend & ot will help you two times in this journey.

So if you look at the keyboard you will get that it was alphanumberic Characters you have to replace them by digits.

s = "^$#^^&###$&$#$&!^&&&%f&@#*^*&^^f^f#^#^@f#&^$&!^a^##(#&^d&@#[email protected]^a#%&(^#^(^##^^&#(&!#$^%@b"
l = len(s)

i = 0

while i<l:
    if(s[i] == '!'):
        print("1" , end='')
    elif(s[i] == '@'):
        print("2", end='')
    elif(s[i] == '#'):
        print("3", end='')
    elif(s[i] == '$'):
        print("4", end='')
    elif(s[i] == '%'):
        print("5", end='')
    elif(s[i] == '^'):
        print("6", end='')
    elif(s[i] == '&'):
        print("7", end='')
    elif(s[i] == '*'):
        print("8", end='')
    elif(s[i] == '('):
        print("9", end='')
    elif(s[i] == ')'):
        print("0", end='')
        print(s[i], end='')

    i = i+1

Script by Odin.

After Running this script you will get the hex value:


After Decode it online you will get the another Encoded Cipher.


Now if you remeber the hint we need keyboard once again so basically it was a Keyboard Shift Cipher after Decoding it you will get:


Seperate each Word By _ and you have your final flag.


You may also like

Leave a Comment