Cross-Platform Keylogger in C

Overview

This project is a cross-platform keylogger written in C that works on Windows, Linux, and macOS. The keylogger captures keystrokes on each platform using appropriate system APIs and logs them into a file named keylog.txt.

Platforms Supported:

• Windows: Uses SetWindowsHookEx to intercept keyboard events.
• Linux: Utilizes the X11 library to capture keystrokes in graphical environments.
• macOS: Employs the CoreGraphics framework to monitor keyboard events.

This is a minimal implementation aimed at security professionals and ethical hackers for testing and educational purposes.

Features

• Logs keystrokes to a file (keylog.txt) across different operating systems.
• Separate implementations for each platform, ensuring compatibility and leveraging native system APIs.
• Minimal code structure that can be extended for more complex logging (e.g., handling special characters or different keyboard layouts).

Requirements

Windows

• A C compiler such as MinGW or Visual Studio.

Linux

• X11 development headers (Install via: sudo apt-get install libx11-dev on Debian/Ubuntu-based systems).

macOS

• Xcode or a working Clang installation, which should be available by default on macOS.

Compilation Instructions

Windows

To compile the keylogger on Windows using MinGW:

gcc -o keylogger keylogger.c -luser32

Linux

Ensure you have the X11 development libraries installed, then compile with:

gcc -o keylogger keylogger.c -lX11

macOS

To compile the keylogger on macOS using the default Clang compiler:

gcc -o keylogger keylogger.c -framework ApplicationServices

Running the Keylogger

Windows

Just run the compiled binary keylogger.exe. It will start logging keystrokes to keylog.txt in the same directory.

Linux

Run the program with elevated permissions (if necessary) to capture global keystrokes:

sudo ./keylogger

macOS

Run the compiled binary:

./keylogger

Make sure to grant permissions if required (macOS may prompt you to allow the application to monitor input).

File Output

The keylogger will write all captured keystrokes to a file named keylog.txt in the same directory as the executable.

Disclaimer

This keylogger is provided for educational purposes only. Use it only in environments where you have explicit permission. Misuse of this software can result in legal consequences.

© 2024 - NEJAN