How to Block Resigning and Repackaging Android & iOS Apps

Last updated December 12, 2022 by Appdome

Learn to Prevent Tampering in Android apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.

What is Tampering?

To ensure your app is protected against unauthorized changes or any modification that can compromise them is critical. Some examples are:

Why Prevent Tampering in Android Apps?

Tamper prevention protects your app against unwanted changes, mods, and hacks  that can negative impact or compromise your mobile business application including financial and data loss, intelectual, privacy & repetitional damage. Appdome prevents all this without adding development work or time to your release cycles.  This is done by sealing your app and actively detecting modifications during initialization and at multiple other points during run-time.

Preventing Tampering on Android apps by Using Appdome

On Appdome, follow these 3 simple steps to create self-defending Android Apps that Prevent Tampering 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
  2. Build the feature: Anti-Tampering.

    1. Building Anti-Tampering by using Appdome’s DEV-API:

      1. Create and name the Fusion Set (security template) that will contain the Anti-Tampering feature as shown below:
      2. fusion set that contains Anti-Tampering

        Figure 1: Fusion Set that will contain the Anti-Tampering 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 Anti-Tampering feature via Appdome Console, to add the Anti-Tampering 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 Anti-Tampering feature via Appdome Console

      To build the Anti-Tampering protection by using Appdome Console, follow the instructions below.

      1. Where: Inside the Appdome Console, go to Build > Security Tab > ONEShield™ section . Like all other options in ONEShield™, Anti-Tampering is turned on by default, as shown below: Anti-Tampering option

        Figure 3: Anti-Tampering option
        Note: The App Compromise Notification contains an easy to follow default remediation path for the mobile app end user. You can customize this message as required to achieve brand specific support, workflow or other messaging.

      2. When you select the Anti-Tampering you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains Anti-Tampering

        Fusion Set applied Anti-Tampering

        Figure 4: Fusion Set that displays the newly added Anti-Tampering protection

      3. Select the Threat-Event™ in-app mobile Threat Defense and Intelligence policy for Anti-Tampering:
        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 Prevent Tampering.

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

          When this setting is used, Appdome detects tampering 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 Anti-Tampering Intelligence and Control in Mobile Apps.

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

          When this setting is used, Appdome detects and defends against Tampering (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 Anti-Tampering Intelligence and Control in Mobile Apps.

      4. Click Build My App at the bottom of the Build Workflow (shown in Figure 3).
    Congratulations!  The Anti-Tampering protection is now added to the mobile app
  3. Certify the Anti-Tampering feature in Android Apps.

    After building Anti-Tampering, Appdome generates a Certified Secure™ certificate to guarantee that the Anti-Tampering protection has been added and is protecting the app. To verify that the Anti-Tampering protection has been added to the mobile app, locate the protection in the Certified Secure™ certificate as shown below: Anti-Tampering shown in Certificate secure

    Figure 5: Certified Secure™ certificate

    Each Certified Secure™ certificate provides DevOps and DevSecOps organizations the entire workflow summary, audit trail of each build, and proof of protection that Anti-Tampering has been added to each Android app. Certified Secure provides instant and in-line DevSecOps compliance certification that Anti-Tampering and other mobile app security features are in each build of the mobile app

Using Threat-Events™ for Tampering Intelligence and Control in Android Apps

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

The specifications and options for Threat-Events™ for Tampering are:

Threat-Event™ Elements Prevent Tampering Method Detail
Appdome Feature Name Anti-Tampering
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 Preventing Tampering Threat-Event™
Threat-Event NAME AppIntegrityError
Threat-Event DATA reasonData
Threat-Event CODE reasonCode
Threat-Event REF 6801
Threat-Event SCORE
currentThreatEventScore Current Threat-Event score
threatEventsScore Total Threat-events score
Threat-Event Context Keys
messageMessage displayed for the user on event
externalIDThe external ID of the event which can be listened via Threat Events
osVersionOS version of the current device
deviceModelCurrent device model
deviceManufacturerThe manufacturer of the current device
fusedAppTokenThe task ID of the Appdome fusion of the currently running app
kernelInfoInfo about the kernel: system name, node name, release, version and machine.
carrierPlmnPLMN of the device
deviceIDCurrent device ID
reasonCodeReason code of the occured event
buildDateAppdome fusion date of the current application
devicePlatformOS name of the current device
carrierNameCarrier name of the current device
updatedOSVersionIs the OS version up to date
deviceBrandBrand of the device
deviceBoardBoard of the device
buildUserBuild user
buildHostBuild host
sdkVersionSdk version
timeZoneTime zone
deviceFaceDownIs the device face down
locationLongLocation long
locationLatLocation lat
locationStateLocation state
wifiSsidWifi SSID
wifiSsidPermissionStatusWifi SSID permission status
AntampIntegrityErrorMessageError message
dataData related to the security event
certificateSHA1Failed certificate

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 Tampering is detected.

The following is a code sample for native Android apps, which uses all values in the specification above for Anti-Tampering:

Prerequisites to Using Anti-Tampering:

To use Appdome’s mobile app security build system to Prevent Tampering , you’ll need:

Using Appdome, there are no development or coding prerequisites to build secured Apps by using Anti-Tampering. 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 Anti-Tampering

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:

All apps protected by Appdome are fully compatible with any public app store, including Apple App Store, Google Play, Huawei App Gallery and more.

Features Similar to Anti-Tampering

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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