Awesome

Frida Injector for Android

is a library allowing you to inject frida agents from an Android application.

The things are very very easy:

Setup

allprojects {
		repositories {
			...
			maven { url 'https://jitpack.io' }
		}
	}

dependencies {
        implementation 'com.github.iGio90:FridaAndroidInjector:+'
}

How to:

    try {
        // build an instance of FridaInjector providing binaries for arm/arm64/x86/x86_64 as needed
        // assets/frida-inject-12.8.2-android-arm64
        FridaInjector fridaInjector = new FridaInjector.Builder(this)
                .withArm64Injector("frida-inject-12.8.2-android-arm64")
                .build();

        // build an instance of FridaAgent
        FridaAgent fridaAgent = new FridaAgent.Builder(this)
                .withAgentFromAssets("agent.js")
                .build();

        // inject systemUi
        fridaInjector.inject(fridaAgent, "com.android.systemui", true);
    } catch (IOException e) {
        e.printStackTrace();
    }

Implementing "on('message')"

    public class MainActivity extends AppCompatActivity implements OnMessage {
        @Override
        public void onMessage(String data) {
            try {
                JSONObject object = new JSONObject(data);
                Log.e("FridaInjector", "SystemUI pid: " + object.getString("pid"));
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    }

    FridaAgent fridaAgent = new FridaAgent.Builder(this)
            .withAgentFromAssets("agent.js")
            .withOnMessage(this)
            .build();

and from your agent

    Java.send({'pid': Process.id});

Implementing sync interfaces

this allows to play with target objects in runtime from your java impl

public class Interfaces {
    static final class ActivityInterface implements FridaInterface {
        @Override
        public Object call(Object[] args) {
            Log.e("FridaAndroidInject", Arrays.toString(args));
            return null;
        }
    }
}

// register a custom interface
fridaAgent.registerInterface("activityInterface", Interfaces.ActivityInterface.class);

and from your agent

var app = Java.use("android.app.Activity");
app.onResume.overloads[0].implementation = function() {
    this.onResume.apply(this, arguments);
    Java.activityInterface(Java.cast(this, app), "otherArg1", "otherArg2");
};

additional

• console.log is redirected to Log.e("FridaAndroidInject", what);

The example apk here is built and ready to try. You will see it works! (only arm64).