Binja Missing Link

A Binary Ninja plugin for analyzing indirect branch targets in x86_64 binaries.

Description

Binja Missing Link is a plugin for Binary Ninja that helps analyze indirect branch targets in x86_64 binaries. It provides detailed information about branch targets, function calls, and virtual table references, making it easier to understand program control flow and function relationships.

Before applying the Binja Missing Link plugin

After applying the Binja Missing Link plugin

Cross reference between branch points

Features

Comment Generation

• Adds detailed comments at branch sources and destinations
• Includes:
  • Target addresses in hexadecimal
  • Function names (when available)
  • Virtual table information (when applicable)
• Supports cross-referencing between branch points

Usage

1. Load your x86_64 binary in Binary Ninja
2. Run the plugin command "Binja Missing Link"
3. Select the JSON file containing branch tracking information
   • The JSON file can be generated by running the LLDB commands (brt_set_bps and brt_save) provided by my LLDB plugin repository.
4. The plugin will analyze the binary and add comments showing:
   • Branch destinations (BML_dst)
   • Branch sources (BML_src)
   • Virtual table references (when applicable)

Input Format

The plugin expects a JSON file with the following structure:

{
    "modules": [
        {
            "name": "module_name",
            "addr": "0xbase_address"
        }
    ],
    "branches": [
        {
            "before": {
                "module": "module_name",
                "func": "function_name",
                "registers": {
                    "rip": "0xaddress",
                    // other register values
                }
            },
            "after": {
                "module": "module_name",
                "func": "function_name",
                "registers": {
                    "rip": "0xaddress",
                    // other register values
                }
            }
        }
    ]
}

Test

# Install pytest
pip install -r test/requirements-test.txt
python3 /Applications/Binary\ Ninja.app/Contents/Resources/scripts/install_api.py --force

# Run tests
pytest test/test_binja_missinglink.py

Author

Koh M. Nakagawa (@tsunek0h) © FFRI Security, Inc. 2025

License

This plugin is released under an Apache 2.0 license.