Lacks's Level 3

Author:
Lacks

Language:
C/C++

Upload:
2026-07-10 17:22

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Platform:
Windows

Difficulty:
2.7

Quality:
5.0

Arch:
x86-64

Downloads:
601

Size:
19.50 KB

Writeups:
2

Comments:
10

Description

This is level 3 im uploading 1 - 10 crack mes

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Comments (10)
Writeups (2)

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brokensociety on 2026-07-10 22:29: [Click to reveal]

dandelion_msla on 2026-07-11 15:11: thanks!

Lover1500 on 2026-07-11 20:02: [Click to reveal]

Toji on 2026-07-13 09:59: [Click to reveal]

sh4man on 2026-07-14 14:59: [Click to reveal]

Phantaso on 2026-07-21 14:47: username FFF Password 266904 keygen generator code v21 = (1337 * v5) ^ 0x5A5A; if ( v24 != v21 ) _n[...] = "\n[-] Access Denied. Key is invalid for this username.\n";

kotsuge on 2026-07-21 21:16: [Click to reveal]

dwxx on 2026-07-22 09:02: [Click to reveal]

ludzof on 2026-07-28 00:13: This level introduces a classic Keygen challenge. Instead of a hardcoded password, it mathematically generates a valid Serial Key based on your Username. By reading the assembly instructions, we can reverse the algorithm: add edx, ecx (Loop): Calculates the sum of all ASCII values in your Username. imul eax, edx, 539: Multiplies that sum by 0x539 (1337 in decimal). xor eax, 5A5A: XORs the result against 0x5A5A (23130 in decimal). The final result is compared against the Serial Key you entered. Since we know the math, we can write a simple Python Keygen to generate valid keys! python def generate_key(username): ascii_sum = sum(ord(c) for c in username) final_key = (ascii_sum * 0x539) ^ 0x5A5A print(f"Serial Key for {username}: {final_key}") # Example: AAAAAAA -> 594453 generate_key("AAAAAAA")

Subhamlmc on 2026-09-10 07:22: I am really progressing with these crackmes. It takes the username , expects the serial key to be a number. doesn't check the total digit entered but it utilizes the username to generate key. Converts all the text into decimal equivalent, sums them all . does multiplication with 1337 and xors the result with 5a5a.

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Solution by MoriartyPuth on 2026-07-14 17:40:

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Solution by MichaelGalaxy on 2026-07-15 18:36:

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crackmes.one

crackmes.one

Lacks's Level 3