Shad3's Baby Ransom

Author:
Shad3

Language:
C/C++

Upload:
2020-05-17 20:49

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Platform:
Unix/linux etc.

Difficulty:
1.5

Quality:
5.0

Arch:
x86-64

Downloads:
22

Size:
9.98 KB

Writeups:
2

Comments:
9

Description

BE CAREFUL PLAYING WITH THIS IT CAN ENCRYPT YOUR FILES. As long as you run it on an isolated folder or a VM you should be fine. The purpose of the challenge is to introduce people to the concept of reverse engineering a baby randomware. The main target of the challenge is to write a decryptor using the language of your choice. P.S. This is for EDUCATIONAL and DEMONSTRATION purposes only, the creator carries no responsibilities if your files get encrypted.

Comments (9)
Writeups (2)

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Shad3 on 2020-05-24 13:11: The bitcoin address is there for demonstration purposes only (if you want to donate to it feel free to) , it belongs to the Free Software Foundation and it was taken from here : https://bitcoinwhoswho.com/blog/2016/02/29/bitcoin-donation-address-rankings/

x0r19x91 on 2020-05-27 11:17: https://paste.ubuntu.com/p/nNm3p2qYMQ/

zed-zahir on 2020-05-27 16:58: the solution I came up with, is you will create one file with null bytes, something like 10 or less, then you let the crypto-ransomware crypt it then you check the encrypted file because when you xor a file with null byte it will give you the key, which here in our situation is '\' 0x5C hex this technique is called null byte attack

js-on on 2020-05-31 16:01: When running it twice, you'll get file.corona.corona files which are completely unencrypted.

zed-zahir on 2020-06-05 22:04: js-on, good point, I didn't think about it!!

sherhack on 2020-06-24 02:29: Fun crackme, looked for you encrytion code and reversed the XoR operation along with the 0xdeadbeef seed

panzo on 2021-03-30 19:12: Fun to do but the fact that the operation used to crypt can be reverse just by re-iterate is not cool :0

jimsktsmith on 2021-12-29 16:21: Solu : Create txt - simple word like 'a' or 'ab' Text xor 92

0xp3rryhu on 2025-07-17 11:44: Pretty cool crackme gj :))

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Solution by 2ourc3 on 2022-12-05 09:33:
Write up by 2ourc3 (bushido-sec.com)

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Solution by NOTALiAR on 2023-05-20 09:41:

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crackmes.one

crackmes.one

Shad3's Baby Ransom