Kick31.zip May 2026

Challenge category: Reverse Engineering / Forensics Difficulty: Medium Points: 250 (typical) The file kick31.zip is a password‑protected ZIP archive. Inside the archive there is a single file named kick31.bin . The goal is to retrieve the flag hidden somewhere in the binary.

[+] Found key: 4c1ck3r! (The key is intentionally short and alphanumeric with a punctuation mark.) 5.1 Run the binary with the key $ ./kick31.bin Enter the key: 4c1ck3r! Congratulations! Here is your flag: FLAGz1p_c0mpre55ion_4w3s0m3 The flag is displayed directly once the correct key is supplied. 5.2 Alternative – Direct extraction If you prefer not to run the binary, you can locate the flag string in the binary’s .rodata section. Using strings : kick31.zip

#!/usr/bin/env python3 import hashlib import itertools import string [+] Found key: 4c1ck3r