Binary Code Obfuscation, Anti-Reversing - Android & iOS

Last updated November 29, 2023 by Appdome

This Knowledge Base article describes how to use Appdome’s AI/ML in your CI/CD pipeline to continuously deliver plugins that Prevent Code Obfuscation in Mobile apps.

Why is Obfuscation Efficient Against Reverse Engineering?

Decompilers have reached a maturity level that allows them to easily recover source code from mobile apps. Binary code obfuscation proved itself as an efficient first line of defense against reverse engineering attempts by hackers. What sets various obfuscation solutions apart is several things: (1) Ease of use (specialized compilers to post-build tools), (2) Performance (some obfuscation methods might impose a performance penalty), and (3) the reference threat level (expertise and time needed to break the defense).

How does Appdome Implement Binary Code Obfuscation?

In iOS, the application’s executable manifests as binary code. Appdome shuffles the code around, so that when the reverse engineering tool attempts to determine the target of a reference, it will appear as though it points to some arbitrary location. On a large scale, this renders the code completely unintelligible. However, the application must contain enough binary code to make the shuffling effective, otherwise it is advisable to use Appdome Flow Relocation as an alternative.

In Android, shared-libraries constitute the native-code part of the app. Appdome uses the loading mechanism of shared libraries in Android and modifies it so encrypted libraries can be loaded. Then, when integrating Binary Code Obfuscation, the native libraries that come with the application get encrypted by using a unique key.

When an attacker attempts to open the protected libraries in a reverse engineering tool, the applications will fail at recognizing the file as binary code.

Prerequisites for Using Appdome's Binary Code Obfuscation Plugins:

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

How to Implement Prevent Code Obfuscation in Mobile Apps Using Appdome

On Appdome, follow these 3 simple steps to create self-defending Mobile Apps that Prevent Code Obfuscation without an SDK or gateway:

  1. Designate the Mobile App to be protected.

    1. Upload an app via the Appdome Mobile Defense platform GUI or via Appdome’s DEV-API or CI/CD Plugins.

    2. Mobile App Formats: .ipa for iOS, or .apk or .aab for Android
    3. Binary Code Obfuscation is compatible with: Obj-C, Java, JS, C#, C++, Swift, Kotlin, Flutter, React Native, Unity, Xamarin, and more.
  2. Select the defense: Binary Code Obfuscation.

      1. Create and name the Fusion Set (security template) that will contain the Binary Code Obfuscation feature as shown below:
        fusion set that contains Binary Code Obfuscation

        Figure 1: Fusion Set that will contain the Binary Code Obfuscation feature

      2. Follow the steps in Sections 2.2-2.2.2 of this article to add the Binary Code Obfuscation feature to your Fusion Set via the Appdome Console.

      3. When you select the Binary Code Obfuscation you'll notice that the Fusion Set you created in step 2.1 now bears the icon of the protection category that contains Binary Code Obfuscation.

        Fusion Set applied Binary Code Obfuscation

        Figure 2: Fusion Set that displays the newly added Binary Code Obfuscation protection
        Note: Annotating the Fusion Set to identify the protection(s) selected is optional only (not mandatory).

      4. Open the Fusion Set Detail Summary by clicking the “...” symbol on the far-right corner of the Fusion Set. Copy the Fusion Set ID from the Fusion Set Detail Summary (as shown below): fusion Set Detail Summary image

        Figure 3: Fusion Set Detail Summary

      5. Follow the instructions below to use the Fusion Set ID inside any standard mobile DevOps or CI/CD toolkit like Bitrise, Jenkins, Travis, Team City, Circle CI or other system:
        1. Refer to the Appdome API Reference Guide for API building instructions.
        2. Look for sample APIs in Appdome’s GitHub Repository.
    1. Add the Binary Code Obfuscation feature to your security template.

      1. Navigate to Build > Security tab > TOTALCode™ Obfuscation section in the Appdome Console.
      2. Toggle On > Binary Code Obfuscation.
        Binary Code Obfuscation option

        Figure 4: Selecting Prevent Code Obfuscation

        Note: The Appdome Platform displays the Mobile Operation Systems supported by each defense in real-time. For more details, see our OS Support Policy KB.

      3. Configure the User Experience Options for Binary Code Obfuscation:
        With Threat-Events™ OFF, Appdome provides several user experience options for mobile brands and developers.
        1. App Compromise Notification: Customize the pop-up or toast Appdome uses to notify the user when a threat is present while using the protected mobile app.
        2. Short message Option. This is available for mobile devices that allow a banner notification for security events.
        3. Localized Message Option. Allows Appdome users to support global languages in security notifications.

          Localized Message

          Figure 5: Default User Experience Options for Appdome’s Code Obfuscation

        4. Binary Code Obfuscation Threat Code™. Appdome uses AI/ML to generate a unique code each time Binary Code Obfuscation is triggered by an active threat on the mobile device. Use the code in Appdome Threat Resolution Center™ to help end users identify, find and resolve active threats on the personal mobile devices.
      4. Extra Configuration with Binary Code Obfuscation:
        1. Favor App’s Size

          Automatically detect and exclude publicly available elements from being obfuscated, to reduce overall application package size.

    2. Initiate the build command either by clicking Build My App at the bottom of the Build Workflow (shown in Figure 4) or via your CI/CD as described in Section 2.1.4.
    Congratulations!  The Binary Code Obfuscation protection is now added to the mobile app
  3. Certify the Binary Code Obfuscation feature in Mobile Apps

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

    Figure 6: 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 Binary Code Obfuscation has been added to each Mobile app. Certified Secure provides instant and in-line DevSecOps compliance certification that Binary Code Obfuscation and other mobile app security features are in each build of the mobile app.

Using Threat-Events™ for Code Obfuscation Intelligence and Control in Mobile Apps

Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when Code Obfuscation is detected. To consume and use Threat-Events™ for Code Obfuscation in Mobile Apps, use AddObserverForName in Notification Center, and the code samples for Threat-Events™ for Code Obfuscation shown below.

The specifications and options for Threat-Events™ for Code Obfuscation are:

Threat-Event™ Elements Prevent Code Obfuscation Method Detail
Appdome Feature Name Binary Code Obfuscation
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 x
Visible in ThreatScope™ x
Developer Parameters for Preventing Code Obfuscation Threat-Event™
Threat-Event NAME
Threat-Event DATA reasonData
Threat-Event CODE reasonCode
Threat-Event REF
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
failSafeEnforce Timed enforcement against the identified threat
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. Only available for Android devices.
deviceID Current device ID
reasonCode Reason code of the occurred event
buildDate Appdome fusion date of the current application
devicePlatform OS name of the current device
carrierName Carrier name of the current device. Only available for Android.
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
threatCode The last six characters of the threat code specify the OS, allowing the Threat Resolution Center to address the attack on the affected device.

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


The following is a code sample for native Mobile apps, which uses all values in the specification above for Binary Code Obfuscation:


Important! Replace all placeholder instances of <Context Key> with the specific name of your threat event context key across all language examples. This is crucial to ensure your code functions correctly with the intended event data. For example, The <Context Key> could be the message, externalID, OS Version, reason code, etc.



Using Appdome, there are no development or coding prerequisites to build secured Mobile Apps by using Binary Code Obfuscation. 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 Binary Code Obfuscation

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:

How Do I Learn More?

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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