Windows Internals

Welcome to the Windows Internals series.

Most people interact with Windows through applications, graphical interfaces, and command-line tools. As security professionals, however, we need to understand what happens underneath the surface.

Whether you’re analyzing malware, exploiting vulnerabilities, developing defensive detections, or performing Red Team operations, Windows Internals provides the foundation for understanding how the operating system behaves.

This series is designed to explain the internal architecture of Windows from first principles. Rather than simply introducing APIs or tools, we’ll explore how Windows actually works and why those implementation details matter from a security perspective.

Who is this series for?

This series is intended for:

Penetration Testers
Red Team Operators
Blue Team Analysts
Malware Analysts
Reverse Engineers
Security Researchers
Students interested in Windows Security

Some familiarity with the Windows operating system and basic C/C++ programming concepts will be helpful, but every topic will be explained as clearly as possible.

What you’ll learn

Throughout this series, we’ll explore topics such as:

Windows architecture
User Mode vs Kernel Mode
Processes and Threads
Virtual Memory
PE (Portable Executable) format
DLL loading
Windows Object Manager
Handles
Access Tokens
Security Descriptors
Windows API and Native API
Process Injection techniques
Process Hollowing
DLL Injection
Windows Security Mechanisms
Debugging fundamentals

Each article builds upon previous concepts, so it’s recommended to follow the series in order.

Why Windows Internals Matter

Many offensive security techniques are built on legitimate operating system functionality.

Understanding topics like:

Process creation
Memory allocation
Handle management
Token privileges
Thread execution

allows you to understand not only how attacks work, but also how defenders detect them.

The goal is not simply to memorize APIs, but to understand the design decisions behind Windows itself.

Prerequisites

While not mandatory, the following knowledge will be helpful:

Basic Operating System concepts
C or C++ programming
Windows command line
Basic cybersecurity concepts

Series Roadmap

The exact roadmap may evolve over time, but topics will generally include:

Windows Architecture
Processes and Threads
Virtual Memory
PE File Format
DLL Loading
Windows Object Manager
Access Tokens
Security Descriptors
Native API
Process Injection
Process Hollowing
Windows Security Mechanisms

Learning Approach

This series emphasizes understanding over memorization.

For every concept we’ll answer questions such as:

Why does Windows work this way?
What problem does this solve?
How do attackers abuse it?
How do defenders detect it?

By the end of the series, you’ll have a much deeper understanding of Windows internals and how that knowledge applies to modern offensive and defensive security.

Let’s begin.