How to Detect Unlocked Bootloader in Android Apps Using AI
This Knowledge Base article describes how to use Appdome’s AI/ML in your CI/CD pipeline to continuously deliver plugins that Detect Unlocked Bootloader in Android apps.
What Are Unlocked Bootloader Attacks?
An Unlocked Bootloader attack involves disabling Android’s bootloader security, granting attackers unrestricted access to the device’s system. Tools like Fastboot and TWRP are commonly used to unlock bootloaders, allowing attackers to install malicious ROMs or tamper with app data and credentials. Detection is challenging because these modifications occur below app-layer defenses. The emergence of AI-based tools automating bootloader unlocking adds complexity, making secure boot and app integrity verification essential for regulatory compliance under frameworks like PCI DSS, which demand protection against unauthorized access.
How Appdome Protects Mobile Apps Against Unlocked Bootloader Attacks?
Appdome’s dynamic Detect Unlocked Bootloader plugin identifies Android devices with unlocked bootloaders, which can expose apps to security risks. The plugin monitors system properties such as ro.boot.flash.locked and ro.boot.verifiedbootstate to detect unlocked states. It also checks for the presence of custom recovery images and unauthorized modifications to the boot partition. Upon detection, the plugin can automatically disable specific app functionalities, log the event, or terminate the session, ensuring the app operates securely and maintains its integrity. Mobile developers can leverage Appdome’s Threat-Events™ to collect detailed data on bootloader events and tailor in-app responses based on detected threats.
Prerequisites for Using Appdome's Detect Unlocked Bootloader Plugins:
To use Appdome’s mobile app security build system to Detect Unlocked Bootloader , you’ll need:
- Appdome account (create a free Appdome account here)
- A license for Detect Unlocked Bootloader
- Mobile App (.apk or .aab for Android)
- Signing Credentials (see Signing Secure Android apps and Signing Secure iOS apps)
How to Implement Detect Unlocked Bootloader in Android Apps Using Appdome
On Appdome, follow these 3 simple steps to create self-defending Android Apps that Detect Unlocked Bootloader 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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Detect Unlocked Bootloader 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: Detect Unlocked Bootloader.
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Follow the steps in Sections 2.2-2.2.2 of this article to add the Detect Unlocked Bootloader feature to your Fusion Set via the Appdome Console.
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When you select the Detect Unlocked Bootloader you'll notice that the Fusion Set you created in step 2.1 now bears the icon of the protection category that contains Detect Unlocked Bootloader.
Figure 2: Fusion Set that displays the newly added Detect Unlocked Bootloader 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 Detect Unlocked Bootloader feature as shown below:Figure 1: Fusion Set that will contain the Detect Unlocked Bootloader feature
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Add the Detect Unlocked Bootloader feature to your security template.
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Navigate to Build > Anti Fraud tab > Mobile Malware Prevention section in the Appdome Console.
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Toggle OnDetect Unlocked Bootloader.
(a) Choose to monitor this attack vector by checking the Threat Events checkbox associated with Detect Unlocked Bootloader as shown below.
(b) To receive mobile Threat Monitoring, check the ThreatScope™ box as shown below. For more details, see our knowledge base article on ThreatScope™ Mobile XDR.Figure 4: Selecting Detect Unlocked Bootloader
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. -
Select the Threat-Event™ in-app mobile Threat Defense and Intelligence policy for Detect Unlocked Bootloader:
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Threat-Events™ OFF > In-App Defense
If the Threat-Events™ setting is not selected. Appdome will detect and defend the user and app by enforcing Unlocked Bootloader.
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Threat-Events™ ON > In-App Detection
When this setting is used, Appdome detects if the bootloader has been unlocked on an Android device on which the protected app is running 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™ to Detect Detect Unlocked Bootloader Intelligence and Control in Mobile Apps.
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Threat-Events™ ON > In-App Defense
When this setting is used, Appdome detects and defends against Unlocked Bootloader (same as Appdome Enforce) and passes Appdome’s Threat-Event™ attack intelligence to 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 Detect Detect Unlocked Bootloader Intelligence and Control in Mobile Apps.
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Configure the User Experience Options for Detect Unlocked Bootloader:
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 Unlocked Bootloader
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Detect Unlocked Bootloader Threat Code™. Appdome uses AI/ML to generate a unique code each time Detect Unlocked Bootloader 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.
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Congratulations! The Detect Unlocked Bootloader protection is now added to the mobile app -
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Certify the Detect Unlocked Bootloader feature in Android Apps
After building Detect Unlocked Bootloader, Appdome generates a Certified Secure™ certificate to guarantee that the Detect Unlocked Bootloader protection has been added and is protecting the app. To verify that the Detect Unlocked Bootloader 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 Detect Unlocked Bootloader has been added to each Android app. Certified Secure provides instant and in-line DevSecOps compliance certification that Detect Unlocked Bootloader and other mobile app security features are in each build of the mobile app.
Using Threat-Events™ for Unlocked Bootloader Intelligence and Control in Android Apps
Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when Unlocked Bootloader is detected. To consume and use Threat-Events™ for Unlocked Bootloader in Android Apps, use registerReceiver in the Application OnCreate, and the code samples for Threat-Events™ for Unlocked Bootloader shown below.
The specifications and options for Threat-Events™ for Unlocked Bootloader are:
Threat-Event™ Elements | Detect Unlocked Bootloader Method Detail |
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Appdome Feature Name | Detect Unlocked Bootloader |
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 Detecting Unlocked Bootloader Threat-Event™ | |
Threat-Event NAME | DetectUnlockedBootloader |
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 | |
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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), 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 Unlocked Bootloader is detected.
The following is a code sample for native Android apps, which uses all values in the specification above for Detect Unlocked Bootloader:
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.
xxxxxxxxxx
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction("DetectUnlockedBootloader");
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);
}
Using Appdome, there are no development or coding prerequisites to build secured Android Apps by using Detect Unlocked Bootloader. 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 Detect Unlocked Bootloader
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 Block SSL Pinning Bypass in Android Apps
- How to Build Root Detection, Protect Android Apps
- How to Detect Magisk Hide 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!
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