hi everyone, in this write-up, I will be discussing the GEMASTIK18 Qualification 2025 Reverse Engineering Challenge #1 - Scripts. Let’s dive into the details!

for this challenge, we were provided with a binary file named main with unfamiliar decompilation code. Our task was to analyze the binary and understand its functionality, ultimately leading to the extraction of a flag.

after further investigation, we discovered that the binary was stripped lua script obfuscated with XOR. we then proceeded to write a script to automate the deobfuscation process, allowing us to recover the flag.

when we ran the script, it successfully deobfuscated the binary and revealed the flag.