Windows Keylogger (Educational Purpose Only)

This is a Windows-based keylogger developed in C++. It captures and logs keystrokes at the system level using Windows Hooks. The project demonstrates how low-level keyboard events can be monitored using the Windows API.

You can checkout https://medium.com/@atharvphadatare78/part-1-learn-building-a-windows-keylogger-with-c-7ad04c1da8c9 ,https://medium.com/@atharvphadatare78/part-2-the-real-spy-work-begins-829674711cdb ,To learn how to build your own keylogger. And I have explained concepts releted to the Keylogger in detail there.

⚠️ DISCLAIMER: This tool is built strictly for educational purposes. Unauthorized use of a keylogger is illegal and unethical. Use it only in lab environments or with explicit permission.

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🔧 Features

• ✅ Captures every key press using a low-level keyboard hook
• ✅ Supports alphanumeric and special characters
• ✅ Detects shift and caps lock to log proper case
• ✅ Writes logs to a hidden file silently
• ✅ Automatically captures locale keyboard layout

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🛠️ Technologies Used

• Language: C++
• Platform: Windows OS
• API: Windows API (Win32)
• Tools: MinGW / Visual Studio Code

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📌 How It Works

1. Windows Hook Setup

The program installs a low-level keyboard hook using SetWindowsHookEx() with the WH_KEYBOARD_LL flag.

2. Hook Callback Function

Each keystroke triggers HookCallback(), which retrieves the key code using a KBDLLHOOKSTRUCT structure.

3. Keystroke Interpretation

It converts virtual key codes into readable characters, accounting for SHIFT and CAPS LOCK to log the correct case.

4. Log Storage

Captured keystrokes are stored in a log file, which can be hidden for stealth operation.

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🚀 Getting Started

✅ Prerequisites

• Windows OS
• MinGW compiler or Visual Studio Build Tools

🔧 Compile and Run

Using g++ via MinGW:

g++ keylogger.cpp -o keylogger.exe -luser32
./keylogger.exe

⚠️ Make sure to run the executable with administrator privileges to hook globally.