Author:
mrAlpha17mr

Language:
C/C++

Upload:
2026-10-31 02:59

Platform:
Windows

Points:
200

Quality:
4.0

Arch:
x86-64

Downloads:
175

Size:
3.53 KB

Solves:
24

Attempts:
76

Description

Goal: write a keygen. Patching a jump is not a solution. mothlight is a porch-light keygenme for Windows x86-64. Run mothlight.exe in a console. It takes one name and one serial from standard input, then exits. It does not use the network, write files, or load any DLL beyond kernel32 and the system C runtime (msvcrt). No packer and no anti-debug. Input name> 3 to 20 characters: letters, digits, spaces, and hyphens. Letter case does not matter. Anything else is rejected. serial> ML-XXXX-YYYY-ZZZZ ML- is literal uppercase. Each group is four hex digits. Lowercase hex digits are accepted. Output Bad name: The porch light ignores that name. Bad shape: That is not a night serial. Wrong serial: The moth circles and does not land. Right serial: The moth lands. Lantern CMO{........}. The success sentence is not stored as plaintext. It is rebuilt from the entered serial, so changing one conditional jump does not print it. Auto-validation name: CrackMes1 The flag is the CMO{........} token that this name prints. No braces or spaces inside the token. Difficulty 2. Three short loops over the name, basic encoding of the success line, no obfuscator. Hint: one pass walks the name forward, one walks it backward, and one cares about position. The three hex groups are not stored in the order those passes run. ML-DEAD-BEEF-0451 is a decoy.

Flag

Log in to submit the flag.

• Solves (24)