Windows User Space Emulator

A high-performance Windows process emulator that operates at syscall level, providing full control over process execution through comprehensive hooking capabilities.

Perfect for security research, malware analysis, and DRM research where fine-grained control over process execution is required.

Built in C++ and powered by the Unicorn Engine.

Key Features

• 🔄 Syscall-Level Emulation
  • Instead of reimplementing Windows APIs, the emulator operates at the syscall level, allowing it to leverage existing system DLLs
• 📝 Advanced Memory Management
  • Supports Windows-specific memory types including reserved, committed, built on top of Unicorn's memory management
• 📦 Complete PE Loading
  • Handles executable and DLL loading with proper memory mapping, relocations, and TLS
• ⚡ Exception Handling
  • Implements Windows structured exception handling (SEH) with proper exception dispatcher and unwinding support
• 🧵 Threading Support
  • Provides a scheduled (round-robin) threading model
• 💾 State Management
  • Supports both full state serialization and fast in-memory snapshots (currently broken 😕)
• 💻 Debugging Interface
  • Implements GDB serial protocol for integration with common debugging tools (IDA Pro, GDB, LLDB, VS Code, ...)

Note

The project is still in a very early, prototypical state. The code still needs a lot of cleanup and many features and syscalls need to be implemented. However, constant progress is being made :)

Preview

YouTube Overview

Click here for the slides.

Build Instructions

Prerequisites

• Windows 64-bit (click here for cross-platform status)
• CMake
• Git
• Rust (pass -DMOMO_ENABLE_RUST_CODE=0 to cmake to disable requirement)

Getting Started

Clone the repository with submodules:

git clone https://github.com/momo5502/emulator.git
cd emulator
git submodule update --init --recursive

Run the following commands in an x64 Development Command Prompt

Visual Studio 2022

cmake --preset=vs2022

Solution will be generated at build/vs2022/emulator.sln

Ninja

Debug build:

cmake --workflow --preset=debug

Release build:

cmake --workflow --preset=release

Dumping the Registry

The emulator needs a registry dump to run, otherwise it will print Bad hive file errors.
You can create one by running the src/tools/grab-registry.bat script as administrator.
This will create a registry folder that needs to be placed in the working directory of the emulator.

Running Tests

The project uses CTest for testing. Choose your preferred method:

Visual Studio:

• Build the RUN_TESTS target

Ninja:

cd build/release  # or build/debug
ctest