Yachay

🐱 GitHub
🧠 Hack The Box
👨‍💻 Root-Me
🕵️ Osintopia

About me

I have expanded my cybersecurity skills and now focus on development and reverse engineering on Windows. I am particularly interested in this field because it allows me to delve into the internal mechanisms of systems and understand their vulnerabilities. My approach is focused on security, ethics, and the optimization of digital tools, with the goal of contributing to more robust cybersecurity that respects privacy. Over time, my interests have expanded to include issues of online privacy, anonymity, respect for personal data, and the use of open source software. These topics are essential to me because they touch not only on technology, but also on fundamental ethical questions and our individual freedom in an increasingly digitized world. ...

Windows PE Reverse Engineering – Crackme #1

Analysis of a 64-bit Windows PE executable, tracing back step by step from the entry point to understand how the program processes user input, using assembly language, the internal workings of PE sections, and deliberately discreet validation logic, revealing a simple but clever mechanism typical of small reverse engineering challenges. Windows PE Reverse Engineering – Crackme #1 Infos: Executable name: crack_me.exe Format: PE32+ Architecture: x86-64 Windows Sections: 3 sections Executable: Console Techniques/Concepts used RIP-relative addressing to access data without an absolute address Data stored directly in the .text section (inline data) Mapping table indexed via a bitwise mask (AND 0x7) Verification loop combining user input and an internal table I use PE-bear, which analyzes files in PE (Portable Executable) format. ...

Windows PE Reverse Engineering – Crackme #2

Step‑by‑step analysis of a 64‑bit Windows PE executable, focusing on entry point analysis, runtime initialization, stack frame inspection, and conditional branching to understand how user input is validated in a basic crackme challenge. Windows PE Reverse Engineering – Crackme #2 Infos: Executable name: 3outof6.exe Format: PE32+ Architecture: x86-64 Windows Sections: 19 sections Executable: Console Techniques/Concepts used RIP-relative addressing to access data without an absolute address DLL imports & IAT (Import Address Table) Environment dependency awareness CRT / Runtime initialization analysis CRT (C RunTime) all code automatically added by the compiler. RIP = address of the next instruction, used for relative addressing in x86‑64. ...