How to Protect Floating Windows and Dynamic Content in Android Apps
Learn to Prevent the visibility of dynamically generated windows on screen grab applications in Android apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.
What is Appdome's Prevent Screen Sharing feature?
Prevent App Screen Sharing is used to ensure sensitive data is not recorded from the app’s screen. Screenshots, mirroring, and sharing the app’s screen is prevented.
The Appdome feature Prevent App Screen Sharing prevents the sharing of screens on Android applications. For full and complete protection, Appdome’s Protect Dynamically Generated Windows (a sub-toggle) secures those Android UI elements that do not expose a developer-facing API, such as Android floating windows.
Why Protect Floating Windows and Dynamically Generated Windows in Android apps?
When a developer sets the FLAG_SECURE for chosen Android UI elements, the underlying infrastructure of Android treats the content of the window as secure, preventing it from appearing in screenshots or from being viewed on non-secure displays. However, due to a design flaw in the Android framework, there are several exceptions. When setting the flag on an Activity or Fragment, the secured protection isn’t inherited by all of its “children” (aka small UI elements), such as various dialogs, floating windows or menus, and popups.
Appdome Protect Dynamically Generated Windows prevents those UI elements’ visibility on screen grab applications ensuring that sensitive data is not recorded from the app’s screen.
Furthermore, on many UI elements, it is fairly difficult to set the FLAG_SECURED, due to lack of a developer-facing API (f.e. Spinner or Toast). On some 3rd party UI frameworks, such as React-Native, the FLAG_SECURED cannot be passed at all without modifying the React-Native framework. Protect Dynamically Generated Windows enables you to protect even those UI elements that do not expose a developer facing API, among many others:
- android.app.DialogFragment
- android.support.v4.app.DialogFragment
- android.app.AlertDialog
- android.support.v7.app.AlertDialog
- android.widget.PopupMenu
- android.widget.PopupWindow
- android.widget.ListPopupWindow
- android.widget.ShareActionProvider
- android.widget.Toast
- android.widget.Toolbar
- android.widget.AutoCompleteTextView
- android.widget.Spinner
- android.app.Dialog
- android.app.DatePickerDialog
- android.app.TimePickerDialog
- android.support.v7.widget.AppCompatSpinner
Prerequisites for Using Protect Dynamically Generated Windows:
To use Appdome’s mobile app security build system to Prevent the visibility of dynamically generated windows on screen grab applications , you’ll need:
- Appdome account (create a free Appdome account here)
- A license for Protect Dynamically Generated Windows
- Mobile App (.apk or .aab for Android)
- Signing Credentials (see Signing Secure Android apps and Signing Secure iOS apps)
Prevent the visibility of dynamically generated windows on screen grab applications on Android apps using Appdome
On Appdome, follow these 3 simple steps to create self-defending Android Apps that Prevent the visibility of dynamically generated windows on screen grab applications without an SDK or gateway:
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Upload the Mobile App to Appdome.
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Upload an app to Appdome’s Mobile App Security Build System
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Upload Method: Appdome Console or DEV-API
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Android Formats: .apk or .aab
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Protect Dynamically Generated Windows Compatible With: Java, JS, C++, C#, Kotlin, Flutter, React Native, Unity, Xamarin, Cordova and other Android apps
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Build the feature: Protect Dynamically Generated Windows.
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Building Protect Dynamically Generated Windows by using Appdome’s DEV-API:
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Create and name the Fusion Set (security template) that will contain the Protect Dynamically Generated Windows feature as shown below:
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Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the Protect Dynamically Generated Windows feature via Appdome Console, to add the Protect Dynamically Generated Windows feature to this Fusion Set.
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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 2: Fusion Set Detail Summary
Note: Annotating the Fusion Set to identify the protection(s) selected is optional only (not mandatory). -
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:
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Build an API for the app – for instructions, see the tasks under Appdome API Reference Guide
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Look for sample APIs in Appdome’s GitHub Repository
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Figure 1: Fusion Set that will contain the Protect Dynamically Generated Windows feature
Note: Naming the Fusion Set to correspond to the protection(s) selected is for illustration purposes only (not required). -
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Building the Protect Dynamically Generated Windows feature via Appdome Console
To build the Protect Dynamically Generated Windows protection by using Appdome Console, follow the instructions below.
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Where: Inside the Appdome Console, go to Build > Security Tab > Mobile Privacy section.
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How: Check whether is toggled On (enabled), otherwise enable it . The feature Protect Dynamically Generated Windows is enabled by default, as shown below. Toggle (turn ON) Protect Dynamically Generated Windows, as shown below.
Figure 3: Prevent the visibility of dynamically generated windows on screen grab applications option
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When you select the Protect Dynamically Generated Windows you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains Protect Dynamically Generated Windows
Figure 4: Fusion Set that displays the newly added Protect Dynamically Generated Windows protection
- Optional Configuration with Protect Dynamically Generated Windows:
- Protect Dynamically Generated Windows
Extends App Screen Sharing Prevention to all Android floating windows.
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Click Build My App at the bottom of the Build Workflow (shown in Figure 3).
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Congratulations! The Protect Dynamically Generated Windows protection is now added to the mobile app -
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Certify the Protect Dynamically Generated Windows feature in Android Apps
After building Protect Dynamically Generated Windows, Appdome generates a Certified Secure™ certificate to guarantee that the Protect Dynamically Generated Windows protection has been added and is protecting the app. To verify that the Protect Dynamically Generated Windows protection has been added to the mobile app, locate the protection in the Certified Secure™ certificate as shown below:
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 Protect Dynamically Generated Windows has been added to each Android app. Certified Secure provides instant and in-line DevSecOps compliance certification that Protect Dynamically Generated Windows and other mobile app security features are in each build of the mobile app
Using Threat-Events™ for the visibility of dynamically generated windows on screen grab applications Intelligence and Control in Android Apps
Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when the visibility of dynamically generated windows on screen grab applications is detected. To consume and use Threat-Events™ for the visibility of dynamically generated windows on screen grab applications in Android Apps, use registerReceiver in the Application OnCreate, and the code samples for Threat-Events™ for the visibility of dynamically generated windows on screen grab applications shown below.
The specifications and options for Threat-Events™ for the visibility of dynamically generated windows on screen grab applications are:
Threat-Event™ Elements | Prevent the visibility of dynamically generated windows on screen grab applications Method Detail |
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Appdome Feature Name | Protect Dynamically Generated Windows |
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 the visibility of dynamically generated windows on screen grab applications 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 |
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 the visibility of dynamically generated windows on screen grab applications is detected.
The following is a code sample for native Android apps, which uses all values in the specification above for Protect Dynamically Generated Windows:
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.
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IntentFilter 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);
}
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val 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)
}
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const { 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...)
}
);
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window.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 Protect Dynamically Generated Windows. 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 Protect Dynamically Generated Windows
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 Screen Sharing Malware
- How to Protect Android & iOS Apps from Copy/Paste Attacks
- How to Use Trusted App Groups with Copy Paste Prevention
- How to Block Team Viewer & Remote Desktop Exploits in Android 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.