Entity-Relation Diagram Assisted Hacking Tool

Intelligent Connected Vehicles and Smartphones contain a large number of APK files, which have intricate call relationships between them. An innovative approach has been proposed to create a visual and interactive call relationship analysis tool. By analyzing the call relationships between APK packages, an entity-relationship diagram is generated. By observing the direction of the arrows, one can intuitively see the call relationships. This tool has been used to identify dozens of engineering mode call chains in vehicle, and by reversing the caller, the engineering mode has been successfully activated, providing an analysis entry for vehicle penetration.

Start web server

cd server && python app.py

Demo: ERH-APK

Generate Apk relation diagram

$ python apk_relation_finder.py -p "car" -d "/opt/car/filesystem/"

 \          =o)
 (o>         /\
_(()_apk2apk_\_V_
 //           \
               \
    -- Powered by Delikely

|████████████████████████████████████████| 549 /549 [100%] in 3:21.4 (3.42/s)
Relation Diagram url: http://127.0.0.1:13337/apk-relation?date=1720891507&project=car

Use browser to open diagram page, http://127.0.0.1:13337/apk-relation?date=1720891507&project=car

Diagram Usage

Find factory/engineer entries

Use the diagram to locate the entry for the factory or engineer.

As shown below, The entry can be found from BtPhone.apk to FactorySettings.apk.

.

After decompiling BtPhone.apk, find that FactorySettings.apk can be opened by using android_secret_code through the Dial Board.

// com.***.btactivity.k218.fragment.BtPhoneFragment
if (this.mEditText.getText().toString().equals("*#1337#*")) {
    try {
        Log.d(TAG, "onClick getLaunchIntentForPackage");
        startActivity(BtApplication.getContext().getPackageManager().getLaunchIntentForPackage("com.debugtools"));
        return;
    } catch (Exception e) {
        Log.d(TAG, "onClick The_app_was_not_found");
        ToastUtils.show(getString(R.string.The_app_was_not_found));
        e.printStackTrace();
        Log.d(TAG, "onClick Exception = " + e);
        return;
    }
}

Timeline

• 2024/07/30 Selected for KCON Arsenal
• 2024/06/26 First public on Off-by-One Conference 2024