How to Prevent Task Hijacking in Android Apps Using AI
This Knowledge Base article describes how to use Appdome’s AI in your CI/CD pipeline to continuously deliver plugins that Prevent Task Hijacking in Android apps.
What Is Task Hijacking?
Task hijacking is an Android attack technique in which a malicious app interferes with a legitimate app’s task during runtime by exploiting Android’s task and activity management model. In Android, a task represents a stack of activities that users experience as a single app session. Task hijacking occurs when an unauthorized activity is able to join, replace, or run within the same task as a trusted app, making attacker-controlled screens appear to be part of the legitimate application.
Because these activities execute within the context of the app’s active task, users typically have no visual indication that the UI has been compromised. This enables attackers to impersonate trusted screens—such as login or authentication flows—and potentially gain access to sensitive user data. Task hijacking leverages standard Android multitasking behavior, including task affinity and exported activity configurations. As a result, it cannot be reliably detected or prevented using static controls alone and requires runtime enforcement to protect active app sessions.
Preventing task hijacking is critical for maintaining UI integrity, protecting sensitive user interactions, and supporting secure authentication requirements in mobile applications.
How Appdome Prevents Task Hijacking in Android Apps?
Appdome’s Prevent Task Hijacking protection focuses specifically on blocking task injection attacks while the app is running in the foreground. At runtime, Appdome locks trusted app activities and enforces task integrity, ensuring that only authorized activities belonging to the protected app are allowed to execute within the app’s active task. This prevents malware or other external processes from injecting activities or running within the context of the app during an active user session.
By validating activity ownership and execution in real time, Appdome blocks unauthorized task injection attempts before a malicious screen can be presented to the user or interact with sensitive workflows. This protection is intentionally scoped to task-level runtime enforcement. Related attack surfaces—such as overlay abuse, credential theft, intent misuse, or broader UI deception—are addressed by other complementary Appdome protections across the platform. This ensures clear responsibility boundaries and avoids overlapping or redundant controls.
Prevent Task Hijacking operates entirely at runtime, requires no code changes or SDKs, and preserves a seamless user experience while protecting active app sessions from task-based exploitation.
Prerequisites for Using Appdome's Prevent Task Hijacking Plugins:
To use Appdome’s mobile app security build system to Prevent Task Hijacking , you’ll need:
- Appdome account (create a free Appdome account here)
- A license for Prevent Task Hijacking
- Mobile App (.apk or .aab for Android)
- Signing Credentials (see Signing Secure Android apps and Signing Secure iOS apps)
How to Implement Prevent Task Hijacking in Android Apps Using Appdome
On Appdome, follow these 3 simple steps to create self-defending Android Apps that Prevent Task Hijacking without an SDK or gateway:
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Designate the Mobile App to be protected.
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Upload an app via the Appdome Mobile Defense platform GUI or via Appdome’s DEV-API or CI/CD Plugins.
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Android Formats: .apk or .aab
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Prevent Task Hijacking is compatible with: Java, JS, C++, C#, Kotlin, Flutter, React Native, Unity, Xamarin, Cordova and other Android apps.
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Select the defense: Prevent Task Hijacking.
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Follow the steps in Sections 2.2-2.2.2 of this article to add the Prevent Task Hijacking feature to your Fusion Set via the Appdome Console.
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When you enable Prevent Task Hijacking you'll notice that the Fusion Set you created in step 2.1 now bears the icon of the protection category that contains Prevent Task Hijacking.
Figure 2: Fusion Set that displays the newly added Prevent Task Hijacking protection
Note: Annotating the Fusion Set to identify the protection(s) selected is optional only (not mandatory). -
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):
Figure 3: Fusion Set Detail Summary
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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:
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Refer to the Appdome API Reference Guide for API building instructions.
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Look for sample APIs in Appdome’s GitHub Repository.
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Create and name the Fusion Set (security template) that will contain the Prevent Task Hijacking feature as shown below:
Figure 1: Fusion Set that will contain the Prevent Task Hijacking feature
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Add the Prevent Task Hijacking feature to your security template.
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Navigate to Build > Anti ATO tab > Android Trojans section in the Appdome Console.
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Toggle On Prevent Task Hijacking > Prevent Task Hijacking.
Figure 4: Selecting Prevent Task Hijacking
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. -
Configure the User Experience Options for Prevent Task Hijacking:
With Threat-Events™ OFF, Appdome provides several user experience options for mobile brands and developers.- 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.
- Short message Option. This is available for mobile devices that allow a banner notification for security events.
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Localized Message Option. Allows Appdome users to support global languages in security notifications.
Figure 5: Default User Experience Options for Appdome’s Task Hijacking
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Prevent Task Hijacking Threat Code™. Appdome uses AI to generate a unique code each time Prevent Task Hijacking 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.
- Optional Configuration with Prevent Task Hijacking:
- Trust Specified Activities Only
Specify the class name of the activity to exclude from Overlay detection
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Congratulations! The Prevent Task Hijacking protection is now added to the mobile app -
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Certify the Prevent Task Hijacking feature in Android Apps
After building Prevent Task Hijacking, Appdome generates a Certified Secure™ certificate to guarantee that the Prevent Task Hijacking protection has been added and is protecting the app. To verify that the Prevent Task Hijacking protection has been added to the mobile app, locate the protection in the Certified Secure™ certificate as shown below:
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 Prevent Task Hijacking has been added to each Android app. Certified Secure provides instant and in-line DevSecOps compliance certification that Prevent Task Hijacking and other mobile app security features are in each build of the mobile app.
Using Threat-Events™ for Task Hijacking Intelligence and Control in Android Apps
Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when Task Hijacking is detected. To consume and use Threat-Events™ for Task Hijacking in Android Apps, use registerReceiver in the Application OnCreate, and the code samples for Threat-Events™ for Task Hijacking shown below.
The specifications and options for Threat-Events™ for Task Hijacking are:
| Threat-Event™ Elements | Prevent Task Hijacking Method Detail |
|---|---|
| Appdome Feature Name | Prevent Task Hijacking |
| 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 Task Hijacking Threat-Event™ | |
| Threat-Event NAME | |
| Threat-Event DATA | reasonData |
| Threat-Event CODE | reasonCode |
| Threat-Event SCORE | |
| currentThreatEventScore | Current Threat-Event score |
| threatEventsScore | Total Threat-events score |
| Threat-Event Context Keys | |
|---|---|
| Timestamp | The exact time the threat event was triggered, recorded in milliseconds since epoch |
| 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. Only available for Android devices. |
| deviceID | Current device ID |
| reasonCode | Reason code of the occurred event |
| deviceBrand | Brand of the device |
| deviceBoard | Board of the device |
| buildUser | Build user |
| buildHost | Build host |
| sdkVersion | Sdk version |
| 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), 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 Task Hijacking is detected.
The following is a code sample for native Android apps, which uses all values in the specification above for Prevent Task Hijacking:
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.
xxxxxxxxxxIntentFilter intentFilter = new IntentFilter();intentFilter.addAction("");BroadcastReceiver threatEventReceiver = new BroadcastReceiver() { public void onReceive(Context context, Intent intent) { String message = intent.getStringExtra("message"); // Message shown to the user String reasonData = intent.getStringExtra("reasonData"); // Threat detection cause String reasonCode = intent.getStringExtra("reasonCode"); // Event reason code // Current threat event score String currentThreatEventScore = intent.getStringExtra("currentThreatEventScore"); // Total threat events score String threatEventsScore = intent.getStringExtra("threatEventsScore"); // Replace '<Context Key>' with your specific event context key // String variable = intent.getStringExtra("<Context Key>"); // Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...) }};if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) { registerReceiver(threatEventReceiver, intentFilter, Context.RECEIVER_NOT_EXPORTED);} else { registerReceiver(threatEventReceiver, intentFilter);}xxxxxxxxxxval intentFilter = IntentFilter()intentFilter.addAction("")val threatEventReceiver = object : BroadcastReceiver() { override fun onReceive(context: Context?, intent: Intent?) { var message = intent?.getStringExtra("message") // Message shown to the user var reasonData = intent?.getStringExtra("reasonData") // Threat detection cause var reasonCode = intent?.getStringExtra("reasonCode") // Event reason code // Current threat event score var currentThreatEventScore = intent?.getStringExtra("currentThreatEventScore") // Total threat events score var threatEventsScore = intent?.getStringExtra("threatEventsScore") // Replace '<Context Key>' with your specific event context key // var variable = intent?.getStringExtra("<Context Key>") // Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...) }}if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) { registerReceiver(threatEventReceiver, intentFilter, Context.RECEIVER_NOT_EXPORTED)} else { registerReceiver(threatEventReceiver, intentFilter)}xxxxxxxxxxconst { ADDevEvents } = NativeModules;const aDDevEvents = new NativeEventEmitter(ADDevEvents);function registerToDevEvent(action, callback) { NativeModules.ADDevEvents.registerForDevEvent(action); aDDevEvents.addListener(action, callback);}export function registerToAllEvents() { registerToDevEvent( "", (userinfo) => Alert.alert(JSON.stringify(userinfo)) var message = userinfo["message"] // Message shown to the user var reasonData = userinfo["reasonData"] // Threat detection cause var reasonCode = userinfo["reasonCode"] // Event reason code // Current threat event score var currentThreatEventScore = userinfo["currentThreatEventScore"] // Total threat events score var threatEventsScore = userinfo["threatEventsScore"] // Replace '<Context Key>' with your specific event context key // var variable = userinfo["<Context Key>"] // Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...) );}x
RegisterReceiver(new ThreatEventReceiver(), new IntentFilter("")); class ThreatEventReceiver : BroadcastReceiver{ public override void OnReceive(Context context, Intent intent) { // Message shown to the user String message = intent.GetStringExtra("message"); // Threat detection cause String reasonData = intent.GetStringExtra("reasonData"); // Event reason code String reasonCode = intent.GetStringExtra("reasonCode"); // Current threat event score String currentThreatEventScore = intent.GetStringExtra("currentThreatEventScore"); // Total threat events score String threatEventsScore = intent.GetStringExtra("threatEventsScore"); // Replace '<Context Key>' with your specific event context key // String variable = intent.GetStringExtra("<Context Key>"); // Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...) }}x
NSNotificationCenter.DefaultCenter.AddObserver( (NSString)"", // Threat-Event Identifier delegate (NSNotification notification) { // Message shown to the user var message = notification.UserInfo.ObjectForKey("message"); // Threat detection cause var reasonData = notification.UserInfo.ObjectForKey("reasonData"); // Event reason code var reasonCode = notification.UserInfo.ObjectForKey("reasonCode"); // Current threat event score var currentThreatEventScore = notification.UserInfo.ObjectForKey("currentThreatEventScore"); // Total threat events score var threatEventsScore = notification.UserInfo.ObjectForKey("threatEventsScore"); // Replace '<Context Key>' with your specific event context key // var variable = notification.UserInfo.ObjectForKey("<Context Keys>"); // Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...) });xxxxxxxxxxwindow.broadcaster.addEventListener("", function(userInfo) { var message = userInfo.message // Message shown to the user var reasonData = userInfo.reasonData // Threat detection cause var reasonCode = userInfo.reasonCode // Event reason code // Current threat event score var currentThreatEventScore = userInfo.currentThreatEventScore // Total threat events score var threatEventsScore = userInfo.threatEventsScore // Replace '<Context Key>' with your specific event context key // var variable = userInfo.<Context Keys> // Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)});x
import 'dart:async';import 'package:flutter/material.dart';import 'package:flutter/services.dart';class PlatformChannel extends StatefulWidget { const PlatformChannel({super.key}); State<PlatformChannel> createState() => _PlatformChannelState();}class _PlatformChannelState extends State<PlatformChannel> { // Replace with your EventChannel name static const String _eventChannelName = ""; static const EventChannel _eventChannel = EventChannel(_eventChannelName); void initState() { super.initState(); _eventChannel.receiveBroadcastStream().listen(_onEvent, onError: _onError); } void _onEvent(Object? event) { setState(() { // Adapt this section based on your specific event data structure var eventData = event as Map; // Example: Accessing 'externalID' field from the event var externalID = eventData['externalID']; // Customize the rest of the fields based on your event structure String message = eventData['message']; // Message shown to the user String reasonData = eventData['reasonData']; // Threat detection cause String reasonCode = eventData['reasonCode']; // Event reason code // Current threat event score String currentThreatEventScore = eventData['currentThreatEventScore']; // Total threat events score String threatEventsScore = eventData['threatEventsScore']; // Replace '<Context Key>' with your specific event context key // String variable = eventData['<Context Keys>']; }); } // Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)}Using Appdome, there are no development or coding prerequisites to build secured Android Apps by using Prevent Task Hijacking. 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 Prevent Task Hijacking
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:
- Customizing, Configuring & Branding Secure Mobile Apps.
- Deploying/Publishing Secure mobile apps to Public or Private app stores.
- Releasing Secured Android & iOS Apps built on Appdome.
Related Articles:
- How to Protect Android & iOS Apps from Keylogging Malware
- How to Block Memory Editing tools for Android & iOS apps
- How to Detect MiTM Proxies, Prevent MiTM Attacks in Android & iOS Apps
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.