JS ReverseLab

A powerful React TypeScript application for deobfuscating, obfuscating, and analyzing JavaScript code with advanced security scanning.

🔗 Live Demo: https://js.murr.li

✨ Features

🔓 Deobfuscation

• Smart Decode: Auto-detects and decodes multiple obfuscation types
• JSFuck: Decode JSFuck obfuscated code (only !+ characters)
• AAEncode: Decode Japanese emoticon-based encoding
• JJEncode: Decode symbol-based encoding
• Base64, URL, Hex, Unicode: Standard encoding formats
• Array Unpacking: Unpack array-based obfuscation

🔒 Obfuscation

• MurrCoder (Extreme): Custom extreme obfuscation with char code arrays and mathematical operations
• MurrCoder (Advanced): Advanced obfuscation with string encoding and variable renaming
• AAEncode, JJEncode: Japanese and symbol-based encoding
• Hex, Unicode, URL, Base64: Standard encoding methods

🛡️ Security Features (WIP)

• 🔒 Malware Scanner: Detects malicious patterns in JavaScript code

  • Identifies base64-encoded eval execution
  • Detects dynamic script injection
  • Finds suspicious function constructors
  • Recognizes cryptocurrency-related code
  • Detects data exfiltration attempts

• ⚠️ Dangerous Pattern Detection:

  • Network requests (XMLHttpRequest, fetch, WebSocket)
  • Cookie and localStorage access
  • innerHTML manipulation (XSS vulnerabilities)
  • Page redirections
  • iframe injections
  • ActiveX usage (IE exploits)

• Security Score: 0-100 rating with threat level classification

• Detailed Threat Reports: Line numbers, severity, and recommendations

💻 Advanced Code Editor

• Monaco Editor Integration: VS Code-like editing experience

  • Syntax highlighting
  • Line numbers
  • Code folding
  • Minimap navigation
  • IntelliSense suggestions
  • Auto-indentation
  • Multiple cursors

• Fallback Mode: Classic textarea for lightweight editing

🎨 UI Features

• Split View Mode: Separate input/output panels for better workflow
• Compare Mode: Side-by-side original vs decoded code
• Multi-language: English, Russian, German
• Dark/Light Theme: Toggle between themes
• Copy/Paste/Download: Easy code management
• Eval Layer Detection: Shows how many layers of eval() wrapping

🔧 Code Tools

• Beautify: Format and prettify JavaScript code
• Minify: Compress code by removing whitespace
• Rename Variables: Obfuscate variable names
• Decode Strings: Decode hex/unicode encoded strings
• Run Code: Execute code directly in the browser

🚀 Quick Start

Development

npm install
npm run dev

Build for Production

npm run build

The compiled static files will be in the dist/ folder, ready for deployment to any static hosting service.

Technologies

• React 18 with TypeScript
• Vite for fast builds
• Monaco Editor for advanced code editing
• Emotion CSS for styling
• Custom security scanner engine

🔒 Security Scanner Details

The built-in security scanner analyzes JavaScript code for:

1. Malware Patterns (Critical/High severity):

   • Base64 encoded eval() execution
   • Dynamic script injections
   • Function constructor usage
   • Cryptocurrency mining code

2. Dangerous Patterns (Medium/High severity):

   • Network communications
   • Cookie/storage access
   • DOM manipulation vulnerabilities
   • Page redirections

3. Obfuscation Detection (Low/Medium severity):

   • JSFuck, AAEncode, JJEncode
   • Heavy variable name obfuscation
   • String encoding patterns

Each threat includes:

• Severity level (Low/Medium/High/Critical)
• Line number location
• Detailed description
• Remediation recommendations

⚠️ Disclaimer

This tool is for educational and legitimate code analysis purposes only. Always verify code functionality and security before use in production. The tool may not decrypt all multi-layered encodings.

📝 Copyright

© 2025 Murr | GitHub: vtstv