How to Use Google Play Signature Validation in Android Apps

Last updated May 6, 2024 by Appdome

Learn to Validate Google Play Signature in Android apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.

Why Should Developers Protect Android Apps From Being Distributed on Alternative Appstores?

Fraudsters and other cyber-criminals often create fake apps by copying or cloning existing popular apps and then repackaging, re-signing, and re-distributing those apps on alternative, malicious, or non-approved app stores. There are many different methods, techniques, and motivations for why this is done.

Here are some of the top reasons cyber-criminals publish mobile apps on alternative app stores:

  • To create fakes, clones, or pirated copies of apps and then masquerade as the original app to divert advertising revenue to fraudulent entities or to generate in-app purchase revenue at the expense of the original app.
  • Embed malware or trojans inside a well-known app to trick users into downloading malware onto their mobile devices.
  • To create game mods to be used in mobile game cheating.
  • To create malicious apps that pose as helpful “utility” apps, such as battery-life extenders, QR code generators, calculators, or productivity apps. Once users are tricked into downloading these apps, the malicious apps often run in the background and monitor user activity or broadcast messages to learn what other apps the user has installed and also learn when they are using those other apps. The malicious app can then be used to phone home to a C&C botnet network to receive malware updates or to trigger screen overlay attacks at very precise times because the imposter app has been monitoring the user or device activity and knows what the user is doing.
  • For instance, to commit mobile click fraud or mobile ad fraud, sometimes these malicious apps monitor broadcast events about app installs and then generate a barrage of fake clicks at the very last minute to take credit for the app install.

Whatever their motivation, malicious actors find it fairly easy to publish fake, malicious, or pirated apps on app stores other than the Google Play Store. They simply download a target app (such as your app) on a Rooted mobile device, modify the app, and then repackage, re-sign, and re-distribute the fake or pirated mobile app to any app store they want.

What is Google Play Signature Validation?

Appdome Google Play Signature Validation validates that apps signed for Google Play Store cannot be distributed through any other app stores by preventing apps from being re-signed and re-distributed on app stores other than Google Play. If Appdome detects that an Android app has been downloaded from an app store other than Google Play, Appdome will prevent the app from running.

Prerequisites for Using Google Play Signature Validation:

To use Appdome’s mobile app security build system to Validate Google Play Signature , you’ll need:

Validate Google Play Signature on Android apps using Appdome

On Appdome, follow these 3 simple steps to create self-defending Android Apps that Validate Google Play Signature without an SDK or gateway:

  1. Upload the Mobile App to Appdome.

    1. Upload an app to Appdome’s Mobile App Security Build System

    2. Upload Method: Appdome Console or DEV-API
    3. Android Formats: .apk or .aab
    4. Google Play Signature Validation Compatible With: Java, JS, C++, C#, Kotlin, Flutter, React Native, Unity, Xamarin, Cordova and other Android apps
  2. Build the feature: Google Play Signature Validation.

    1. Building Google Play Signature Validation by using Appdome’s DEV-API:

      1. Create and name the Fusion Set (security template) that will contain the Google Play Signature Validation feature as shown below:
      2. fusion set that contains Google Play Signature Validation

        Figure 1: Fusion Set that will contain the Google Play Signature Validation feature
        Note: Naming the Fusion Set to correspond to the protection(s) selected is for illustration purposes only (not required).

      3. Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the Google Play Signature Validation feature via Appdome Console, to add the Google Play Signature Validation feature to this Fusion Set.

      4. Open the Fusion Set Detail Summary by clicking the “...” symbol on the far-right corner of the Fusion Set, as shown in Figure 1 above, and get the Fusion Set ID from the Fusion Set Detail Summary (as shown below): fusion Set Detail Summary image

        Figure 2: Fusion Set Detail Summary
        Note: Annotating the Fusion Set to identify the protection(s) selected is optional only (not mandatory).

      5. Follow the instructions below to use the Fusion Set ID inside any standard mobile DevOps or CI/CD toolkit like Bitrise, App Center, Jenkins, Travis, Team City, Cirlce CI or other system:
        1. Build an API for the app – for instructions, see the tasks under Appdome API Reference Guide
        2. Look for sample APIs in Appdome’s GitHub Repository
    2. Building the Google Play Signature Validation feature via Appdome Console

      To build the Google Play Signature Validation protection by using Appdome Console, follow the instructions below.

      1. Where: Inside the Appdome Console, go to Build > Anti Fraud Tab > Social Engineering Prevention section.
      2. When you select the Google Play Signature Validation you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains Google Play Signature Validation

        Fusion Set applied Google Play Signature Validation

        Figure 4: Fusion Set that displays the newly added Google Play Signature Validation protection

      3. Select the Threat-Event™ in-app mobile Threat Defense and Intelligence policy for Google Play Signature Validation:
        1. Threat-Events™ OFF > In-App Defense

          If the Threat-Events™ setting is cleared (not selected). Appdome will detect and defend the user and app by enforcing Validate Google Play Signature.

        2. Threat-Events™ ON > In-App Detection

          When this setting is used, Appdome detects an attempt to run an app downloaded from a non-authorized App Store and passes Appdome’s Threat-Event™ attack intelligence to the app’s business logic for processing, enforcement, and user notification. For more information on consuming and using Appdome Threat-Events™ in the app, see section Using Threat-Events™ for Google Play Signature Validation Intelligence and Control in Mobile Apps.

        3. Threat-Events™ ON > In-App Defense

          When this setting is used, Appdome detects and defends against Google Play Signature (same as Appdome Enforce) and passes Appdome’s Threat-Event™ attack intelligence the app’s business logic for processing. For more information on consuming and using Appdome Threat-Events™ in the app, see section Using Threat-Events™ for Google Play Signature Validation Intelligence and Control in Mobile Apps.

      4. Click Build My App at the bottom of the Build Workflow (shown in Figure 3).
    Congratulations!  The Google Play Signature Validation protection is now added to the mobile app

Using Threat-Events™ for Google Play Signature Intelligence and Control in Android Apps

Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when Google Play Signature is detected. To consume and use Threat-Events™ for Google Play Signature in Android Apps, use registerReceiver in the Application OnCreate, and the code samples for Threat-Events™ for Google Play Signature shown below.

The specifications and options for Threat-Events™ for Google Play Signature are:

Threat-Event™ Elements Validate Google Play Signature Method Detail
Appdome Feature Name Google Play Signature Validation
Threat-Event Mode
OFF, IN-APP DEFENSE Appdome detects, defends and notifies user (standard OS dialog) using customizable messaging.
ON, IN-APP DETECTION Appdome detects the attack or threat and passes the event in a standard format to the app for processing (app chooses how and when to enforce).
ON, IN-APP DEFENSE Uses Appdome Enforce mode for any attack or threat and passes the event in a standard format to the app for processing (gather intel on attacks and threats without losing any protection).
Certified Secure™ Threat Event Check
Visible in ThreatScope™
Developer Parameters for Validating Google Play Signature Threat-Event™
Threat-Event NAME NotInstalledFromOfficialStore
Threat-Event DATA reasonData
Threat-Event CODE reasonCode
Threat-Event REF 6902
Threat-Event SCORE
currentThreatEventScore Current Threat-Event score
threatEventsScore Total Threat-events score
Threat-Event Context Keys
message Message displayed for the user on event
externalID The external ID of the event which can be listened via Threat Events
osVersion OS version of the current device
deviceModel Current device model
deviceManufacturer The manufacturer of the current device
fusedAppToken The task ID of the Appdome fusion of the currently running app
kernelInfo Info about the kernel: system name, node name, release, version and machine.
carrierPlmn PLMN of the device
deviceID Current device ID
reasonCode Reason code of the occured event
buildDate Appdome fusion date of the current application
devicePlatform OS name of the current device
carrierName Carrier name of the current device
updatedOSVersion Is the OS version up to date
deviceBrand Brand of the device
deviceBoard Board of the device
buildUser Build user
buildHost Build host
sdkVersion Sdk version
timeZone Time zone
deviceFaceDown Is the device face down
locationLong Location longitude conditioned by location permission
locationLat Location latitude conditioned by location permission
locationState Location state conditioned by location permission
wifiSsid Wifi SSID
wifiSsidPermissionStatus Wifi SSID permission status

With Threat-Events™ enabled (turned ON), Android developers can get detailed attack intelligence and granular defense control in Android applications and create amazing user experiences for all mobile end users when Google Play Signature is detected.

The following is a code sample for native Android apps, which uses all values in the specification above for Google Play Signature Validation:


Using Appdome, there are no development or coding prerequisites to build secured Android Apps by using Google Play Signature Validation. There is no SDK and no library to code or implement in the app and no gateway to deploy in your network. All protections are built into each app and the resulting app is self-defending and self-protecting.

Releasing and Publishing Mobile Apps with Google Play Signature Validation

After successfully securing your app by using Appdome, there are several available options to complete your project, depending on your app lifecycle or workflow. These include:

Related Articles:

If you have any questions, please send them our way at support.appdome.com or via the chat window on the Appdome platform.

Thank you!

Thanks for visiting Appdome! Our mission is to secure every app on the planet by making mobile app security easy. We hope we’re living up to the mission with your project.

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