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UREngine is undergoing a major refactoring phase and development has not been halted. Progress has simply slowed due to personal work commitments.

Attached is the current progress:

UI.ong

📖 Introduction

In the field of mobile game development and security research, Unity engine has occupied an important position with its cross-platform capabilities and IL2CPP backend technology. However, the process of IL2CPP converting C# code to native C++ code and then compiling it to machine code has brought unprecedented challenges to reverse engineering. Traditional decompilation tools often struggle when facing Unity IL2CPP-built applications, with low analysis efficiency and difficult-to-understand results.

It is against this technical background that UnityReverseEngine (UREngine for short) came into being - a completely independently developed professional Unity decompilation engine specifically designed to address the pain points of IL2CPP reverse engineering.


🎯 Technical Background and Challenges

Complexity of Unity IL2CPP

Unity's IL2CPP technology converts managed C# code to native machine code, which includes:

Conversion Stage Description Challenge
IL Conversion C# → IL → C++ → Machine Code Multi-layer conversion causes semantic loss
Garbage Collection Complex memory management logic Reference relationships difficult to track
Type Mapping Managed type to native type conversion Type information obfuscation
Call Optimization Inlining, virtual function tables, etc. Control flow becomes complex

Limitations of Traditional Tools

Problems faced by traditional decompilation tools:

  • Slow Analysis Speed: Need to analyze the entire binary file comprehensively
  • Serious Semantic Loss: Original C# semantics lost in multi-layer conversion
  • Poor Readability: Generated pseudo-code is difficult to understand and use

🌟 UREngine's Technical Breakthroughs

⚡ Ultimate Decompilation Speed

UREngine abandons the full-analysis mode of traditional decompilers and adopts a revolutionary function-level precision analysis strategy:

Core Optimization Technologies

Optimization Feature Effect Innovation
Metadata-Driven Precise function signature identification Avoid blind analysis
Micro Runtime Lightweight runtime simulation No need for complete reconstruction
Smart CFG Remove redundant nodes Highly optimized control flow

Performance Metrics

Metric UREngine Traditional Tools Improvement Factor
Single Function Analysis Millisecond-level Second-level ×1000
Large Games (100K+ functions) 2-5 minutes Several hours ×50
Memory Usage Low consumption High consumption 80% savings

Industry-Leading Pseudocode Analysis Capabilities

UREngine has reached unprecedented heights in ARM64 instruction semantic restoration:

Complex Instruction Processing Examples

1. BLR Indirect Jump Analysis

// Traditional tool output (hard to understand) BLR X8 // X8 = *(_QWORD *)(v6 + 0x48) // Completely unable to understand call intent
// UREngine output (clear and readable) virtualMethod.Invoke(this, parameters); // Perfect restoration of virtual function call semantics

2. SIMD Vector Operation Analysis

// Traditional tool output FADD V0.4S, V1.4S, V2.4S LD1 {V3.4S}, [X0] ST1 {V0.4S}, [X1]
// UREngine output Vector4 result = Vector4.Add(vector1, vector2); transform.position = result;

3. Multi-level Pointer Dereference

// Traditional tool output v8 = *(_QWORD *)(v6 + 0x20); v9 = *(_QWORD *)(v8 + 0x18); v10 = *(_DWORD *)(v9 + 0x10);
// UREngine output int health = player.character.stats.health;

4. Unity Component System Analysis

// Traditional tool output sub_1234ABCD(v7, v8, v9); // Completely unclear what it's doing
// UREngine output GetComponent<Rigidbody>().AddForce(Vector3.up * jumpForce);

Unique Direct C# Semantic Conversion

This is UREngine's most revolutionary feature - the world's only decompilation tool that supports direct conversion from ARM64 instructions to C# code:

Complete Class Restoration Example

Original Unity C# Code:

public class PlayerController : MonoBehaviour { public float moveSpeed = 5f; public float jumpForce = 10f; private Rigidbody rb; void Start() { rb = GetComponent<Rigidbody>(); } void Update() { float horizontal = Input.GetAxis("Horizontal"); Vector3 movement = new Vector3(horizontal, 0, 0) * moveSpeed; transform.Translate(movement * Time.deltaTime); if (Input.GetKeyDown(KeyCode.Space)) { rb.AddForce(Vector3.up * jumpForce, ForceMode.Impulse); } } }

UREngine Restoration Result:

// Nearly perfect restoration! public class PlayerController : MonoBehaviour { public float moveSpeed; // = 5f (default value inferred from binary) public float jumpForce; // = 10f private Rigidbody rb; private void Start() { // Automatically identifies Unity API calls this.rb = base.GetComponent<Rigidbody>(); } private void Update() { // Perfect restoration of input handling logic float horizontal = Input.GetAxis("Horizontal"); Vector3 vector = new Vector3(horizontal, 0f, 0f) * this.moveSpeed; base.transform.Translate(vector * Time.deltaTime); // Accurate restoration of key detection and physics operations if (Input.GetKeyDown(KeyCode.Space)) { this.rb.AddForce(Vector3.up * this.jumpForce, ForceMode.Impulse); } } }

Complex Game Logic Restoration Example

Game State Manager Restoration:

// Game manager perfectly restored by UREngine public class GameManager : MonoBehaviour { public static GameManager Instance { get; private set; } public enum GameState { Menu, Playing, Paused, GameOver } public GameState currentState; public int score; public int lives; private void Awake() { // Singleton pattern automatically identified if (Instance == null) { Instance = this; DontDestroyOnLoad(gameObject); } else { Destroy(gameObject); } } public void ChangeState(GameState newState) { // State machine logic completely restored switch (newState) { case GameState.Menu: Time.timeScale = 1f; UIManager.Instance.ShowMenu(); break; case GameState.Playing: Time.timeScale = 1f; UIManager.Instance.HideMenu(); break; case GameState.Paused: Time.timeScale = 0f; UIManager.Instance.ShowPauseMenu(); break; case GameState.GameOver: Time.timeScale = 0f; UIManager.Instance.ShowGameOverScreen(); SaveHighScore(); break; } currentState = newState; } private void SaveHighScore() { // PlayerPrefs operations automatically identified int highScore = PlayerPrefs.GetInt("HighScore", 0); if (score > highScore) { PlayerPrefs.SetInt("HighScore", score); PlayerPrefs.Save(); } } }

Core Technical Architecture Analysis

Multi-layer Analysis Pipeline

APK/IPA Input → Binary Extraction → Metadata Parsing → ARM64 Disassembly ↓ CFG Construction → ISIL Intermediate Representation → Data Flow Analysis → C# Syntax Reconstruction ↓ Code Optimization → Quality Analysis → Unity Project Reconstruction 

Intelligent Analysis Engine

Analysis Feature Function Description Technical Advantage
Context Awareness Smart inference based on Unity framework features Accurate Unity API call identification
Pattern Recognition Automatic identification of common Unity programming patterns Restoration of design patterns and architecture
Exception Optimization Smart cleanup of IL2CPP redundant exception handling Generate clean, readable code

Extensible Plugin Architecture

  • Instruction Set Plugins: Support for ARM64, x86/x64, RISC-V, etc.
  • Analysis Plugins: CFG optimization, data flow analysis, code quality detection
  • Output Format Plugins: C# source code, Unity projects, documentation reports

🎯 Practical Application Scenarios

Game Security Research

Anti-cheat Mechanism Analysis

// UREngine can perfectly restore game anti-cheat logic public class AntiCheatSystem : MonoBehaviour { private float lastUpdateTime; private Vector3 lastPosition; private float maxSpeed = 10f; private void Update() { // Speed detection restoration float deltaTime = Time.time - lastUpdateTime; float distance = Vector3.Distance(transform.position, lastPosition); float speed = distance / deltaTime; if (speed > maxSpeed) { // Cheat detection logic ReportCheat("SPEED_HACK", speed); } lastPosition = transform.position; lastUpdateTime = Time.time; } }

Network Communication Protocol Restoration

// Network protocol and encryption logic complete restoration public class NetworkManager : MonoBehaviour { private void SendPlayerData(PlayerData data) { // Data serialization and encryption logic restoration byte[] serializedData = JsonUtility.ToJson(data).ToBytes(); byte[] encryptedData = EncryptionUtils.Encrypt(serializedData, secretKey); // Network sending logic NetworkClient.Send(PacketType.PlayerUpdate, encryptedData); } }

Reverse Engineering Learning and Research

Game AI Behavior Tree Restoration

// Complex AI behavior logic complete restoration public class EnemyAI : MonoBehaviour { public enum AIState { Patrol, Chase, Attack, Flee } public AIState currentState; public float detectionRange = 10f; public float attackRange = 2f; public float health = 100f; private void Update() { GameObject player = GameObject.FindWithTag("Player"); float distanceToPlayer = Vector3.Distance(transform.position, player.transform.position); // State machine logic complete restoration switch (currentState) { case AIState.Patrol: if (distanceToPlayer < detectionRange) { currentState = AIState.Chase; } break; case AIState.Chase: if (distanceToPlayer < attackRange) { currentState = AIState.Attack; } else if (distanceToPlayer > detectionRange * 1.5f) { currentState = AIState.Patrol; } break; case AIState.Attack: if (health < 20f) { currentState = AIState.Flee; } else if (distanceToPlayer > attackRange) { currentState = AIState.Chase; } break; } } }

Project Recovery and Migration

Complete Unity Project Structure Restoration

RestoredProject/ ├── Assets/ │ ├── Scripts/ │ │ ├── PlayerController.cs │ │ ├── GameManager.cs │ │ ├── UIManager.cs │ │ └── EnemyAI.cs │ ├── Prefabs/ │ │ ├── Player.prefab │ │ ├── Enemy.prefab │ │ └── UI Canvas.prefab │ └── Scenes/ │ ├── MainMenu.unity │ ├── GameLevel.unity │ └── Settings.unity └── ProjectSettings/ └── (Auto-reconstructed project configuration) 

MOD Development Support

Game Built-in MOD Interface Discovery

// UREngine can discover game's reserved MOD interfaces public class ModManager : MonoBehaviour { public static ModManager Instance; // Discovered MOD loading interface public void LoadMod(string modPath) { // MOD loading logic restoration Assembly modAssembly = Assembly.LoadFrom(modPath); Type[] modTypes = modAssembly.GetTypes(); foreach (Type type in modTypes) { if (type.GetInterface("IGameMod") != null) { IGameMod mod = Activator.CreateInstance(type) as IGameMod; mod.Initialize(); } } } }

Core Technical Innovation Highlights

Original Technical Breakthroughs

Innovation Global Position Technical Advantage
ARM64→C# Conversion World's First Breaking traditional limitations
IL2CPP Runtime Simulation Unique Technology Efficient and precise analysis
Unity-specific CFG Original Algorithm Targeted optimization

Engineering Advantages

Comparison Dimension UREngine Traditional Tools
Performance Speed 9/10 3/10
Analysis Accuracy 8.5/10 4/10
Code Readability 9/10 3/10
Usability 8/10 5/10
Extensibility 9/10 4/10
Stability 8/10 6/10

Complete Ecosystem

Tool Chain Integration

  • dnSpy Integration: View restored code directly in debugger
  • IDA Plugin: Collaborate with traditional tools
  • Visual Studio Support: Seamless code editing experience

Multi-platform Support

  • Windows: Native high-performance support
  • macOS: Complete functionality support
  • Linux: Server environment support

Success Case Studies

Large Commercial Game Analysis

Game Type Function Count Analysis Time Success Rate Code Quality
Runner Game 25,000+ 1.5 minutes 92% ⭐⭐⭐⭐⭐
Shooter Game 80,000+ 4 minutes 88% ⭐⭐⭐⭐
Card Game 150,000+ 8 minutes 85% ⭐⭐⭐⭐
Strategy Game 200,000+ 12 minutes 83% ⭐⭐⭐⭐

Technical Metrics Achievement

Metric Achievement
Analysis Speed 10-50x improvement over traditional tools
Accuracy Rate Function analysis success rate 85%+
Readability Generated code directly compilable and runnable
Completeness Supports complete Unity project reconstruction

Conclusion

UnityReverseEngine is currently under continuous optimization, and this is a technically challenging project. Although significant technical breakthroughs have been achieved at this stage, we are well aware that there is still significant room for improvement.

🎯 Near-term Development Goals

Our initial goal is to improve the function analysis success rate from the current 85% to 95% or higher, which means:

  • More Precise Type Inference: Further improve IL2CPP metadata parsing algorithms
  • Smarter Control Flow Analysis: Optimize restoration accuracy of complex branch structures
  • More Complete Exception Handling: Improve identification capabilities for exception capture and handling logic
  • Broader Instruction Set Support: Extend support for more ARM64 instruction variants

🔧 Technical Optimization Directions

  • Performance Optimization: Further improve analysis speed while ensuring accuracy
  • Stability Enhancement: Reduce analysis failure rates in complex game scenarios
  • User Experience Improvement: Provide more friendly error messages and debugging information
  • Ecosystem Completion: Enhance integration with mainstream development tools

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