How to Build Anti-Debugging in Android & iOS Apps

Last updated June 3, 2024 by Appdome

Learn to Block Debugging Tools in Mobile apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.

What are Debugging Tools?

All the time and effort invested in designing, developing, and testing a mobile app can be endangered if your secret information – namely, algorithms, business logic, and unique data – is stolen by extracting your design.

The discipline for extracting design from a product is called Reverse-Engineering, and has two main categories:

  • Static: Extracting the design of the application without running it, just inspecting its contents.
  • Dynamic: Extracting information about the inner workings of the application by running it in its target or controlled (emulator) environment, and using various tools to inspect the data processing of an application while it runs. This is also known as debugging.

This Knowledge Base article explains Appdome’s Anti-Debugging capabilities, a key component of ONEShield™ by Appdome, which Appdome automatically adds to every app built using Appdome.

Why Block Debugging Tools in Mobile Apps?

Debugging Tools are software tools that will allow malicious users to debug your application. Some of them are very versatile and allow you to communicate with your device and facilitate a variety of device actions including installing and debugging apps, as well as access to shell commands to run a variety of commands on a device.

Appdome’s Anti-Debugging counters and stunts malicious dynamic reverse-engineering attempts on your application.

With Block Debugging Tools, developers can achieve the following in Android:

  • Attempting to attach to the process with a debugger, tracing tool or code injectors will result in the application misbehaving, and eventually terminating.
  • Attempting to debug the Java Virtual Machine (JVM) by using JDB (or anything that utilizes the JDWP protocol) will disconnect the debugger.

in iOS, connecting with a debugger will cause the debugging client (lldb) to:

  • Halt.
  • After a sufficient wait time, the debug session will terminate and the debugger will crash.

These are the basic measures Appdome takes to make sure an attacker has to resort to other techniques such as tampering and static reversing. Both of which are protected by Appdome’s Anti-Tampering and Anti-Emulator . This three-pronged defense gives an all-around effective hardening for your mobile app.

Prerequisites for Using Anti Debugging:

To use Appdome’s mobile app security build system to Block Debugging Tools , you’ll need:

Block Debugging Tools on Mobile apps using Appdome

On Appdome, follow these 3 simple steps to create self-defending Mobile Apps that Block Debugging Tools 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. Mobile App Formats: .ipa for iOS, or .apk or .aab for Android
    4. Anti Debugging Compatible With: Obj-C, Java, JS, C#, C++, Swift, Kotlin, Flutter, React Native, Unity, Xamarin, and more
  2. Build the feature: Anti Debugging.

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

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

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

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

      1. Where: Inside the Appdome Console, go to Build > Security Tab > ONEShield™ section.
      2. When you select the Anti Debugging 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 Debugging

        Fusion Set applied Anti Debugging

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

      3. Select the Threat-Event™ in-app mobile Threat Defense and Intelligence policy for Anti Debugging:
        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 Block Debugging Tools.

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

          When this setting is used, Appdome detects Debugging Tools 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 Debugging Intelligence and Control in Mobile Apps.

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

          When this setting is used, Appdome detects and defends against Debugging Tools (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 Debugging 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 Debugging protection is now added to the mobile app

Using Threat-Events™ for Debugging Tools Intelligence and Control in Mobile Apps

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

The specifications and options for Threat-Events™ for Debugging Tools are:

Threat-Event™ Elements Block Debugging Tools Method Detail
Appdome Feature Name Anti Debugging
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 Blocking Debugging Tools Threat-Event™
Threat-Event NAME DebuggerThreatDetected
Threat-Event DATA reasonData
Threat-Event CODE reasonCode
Threat-Event REF 6918
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
reason Reason for detection

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 Debugging Tools are detected.

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


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

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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