Binder Trace is a tool for intercepting and parsing Android Binder messages. Think of it as "Wireshark for Binder".

You'll need a rooted Android device or emulator.

• (Linux only) - install xclip or xsel for "copy to clipboard" functionality

  sudo apt-get install xclip

  sudo apt-get install xsel

• Clone the repo and install python dependencies

  pip install -r binder_trace/requirements.txt

• Check which version of frida is installed (make sure you've pip installed the requirements)

  pip list | grep frida

• Download the matching version of frida-server from the frida releases page

• Make sure adb is running as root, push frida-server to your device and run it

  adb root

  adb push frida-server /data/local/tmp

  chmod u+x /data/local/tmp/frida-server

  adb shell /data/local/tmp/frida-server

To start binder trace we need to pick a device and process to attach to. In the following example we use adb and frida-ps to identify a process to attach to on a local emulator. As it's an Android 11 emulator we choose the Android 11 structs directory. Pick the struct directory that most closely matches your version of Android. If you would like structures for a different version of Android, please let us know. Once it's running start using the target app to generate some binder transactions.

> adb devices
List of devices attached
emulator-5554   device

> frida-ps -Ua
 PID  Name           Identifier
----  -------------  ----------------------------
8334  Messaging      com.android.messaging
7941  Phone          com.android.dialer
9607  Settings       com.android.settings

> cd binder_trace
> python -m binder_trace -d emulator-5554 -n Messaging -s ../structs/android11

If you're interested in specific messages you can filter the displayed results with the following options.

• Interface - limit results to interfaces that contain the case sensitive search string e.g. "com.android" or "Sms".
• Method - limit results to function names containing the specified case sensitive string.
• Type - Limit results to certain types of messages e.g. requests or responses.

Once you've entered your filter options just press Enter to apply them.