How to Prevent Fake iOS Apps using Signature Validation
Learn to Prevent the running of non-authorized apps in iOS apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.
Why Should Developers Prevent the Running of non-authorized apps?
Fraudsters and other cyber-criminals often use various methods and techniques to create fake apps by copying or cloning existing popular apps and then repackaging, re-signing, and re-distributing those apps on alternative, malicious or non-approved app stores. it is fairly easy for malicious actors to publish fake, malicious or pirated apps on app stores other than Apple’s App Store. They only need to download a target app (such as your app) on a Jailbroken mobile device, modify the app, and then repackage, re-sign, and re-distribute the fake or pirated mobile app to any app store they want.
For additional information, see Top Reasons Cyber-criminals Publish Mobile Apps on Alternative App Stores.
How does Appdome Prevent the Running of non-Authorized Apps?
Appdome App Store Validation validates that apps signed for Apple App Store cannot be distributed through any other app stores. If the original app was signed for Apple’s App Store, Appdome prevents the app from being re-signed with a different application identifier. If the app was originally published to the app store, and the application identifier is different than the originally signed app, Appdome detects the difference and prevents the app from running.
Preventing the running of non-authorized apps on iOS apps by Using Appdome
On Appdome, follow these 3 simple steps to create self-defending iOS Apps that Prevent the running of non-authorized apps 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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iOS Formats: .ipa
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Build the feature: App Store Signature Validation.
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Building App Store Signature Validation by using Appdome’s DEV-API:
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Create and name the Fusion Set (security template) that will contain the App Store Signature Validation feature as shown below:
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Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the App Store Signature Validation feature via Appdome Console, to add the App Store Signature Validation 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, as shown in Figure 1 above, and get 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, Cirlce 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 App Store Signature Validation 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 App Store Signature Validation feature via Appdome Console
To build the App Store Signature Validation protection by using Appdome Console, follow the instructions below.
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Where: Inside the Appdome Console, go to Build > Anti Fraud Tab > Mobile Cheat Prevention section
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How: Toggle (turn ON) App Store Signature Validation, as shown below.
If needed, Customize the Threat Notification to be displayed to the mobile end-user in a standard OS dialog notification when Appdome Prevents the running of non-authorized apps.Figure 3: Prevent the running of non-authorized apps option
Note: The App Compromise Notification contains an easy to follow default remediation path for the mobile app end user. You can customize this message as required to achieve brand specific support, workflow or other messaging. -
When you select the App Store Signature Validation you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains App Store Signature Validation
Figure 4: Fusion Set that displays the newly added App Store Signature Validation protection
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Select the Threat-Event™ in-app mobile Threat Defense and Intelligence policy for App Store Signature Validation:
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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 Prevent the running of non-authorized apps.
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Threat-Events™ ON > In-App Detection
When this setting is used, Appdome detects an attempt to install an app from a non-official App Store. 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 App Store Signature Validation 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 the running of non-authorized apps (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 App Store Signature Validation Intelligence and Control in Mobile Apps.
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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 App Store Signature Validation protection is now added to the mobile app -
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Certify the App Store Signature Validation feature in iOS Apps.
After building App Store Signature Validation, Appdome generates a Certified Secure™ certificate to guarantee that the App Store Signature Validation protection has been added and is protecting the app. To verify that the App Store Signature Validation 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 App Store Signature Validation has been added to each iOS app. Certified Secure provides instant and in-line DevSecOps compliance certification that App Store Signature Validation and other mobile app security features are in each build of the mobile app
Using Threat-Events™ for the running of non-authorized apps Intelligence and Control in iOS Apps
Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when the running of non-authorized apps is detected. To consume and use Threat-Events™ for the running of non-authorized apps in iOS Apps, use AddObserverForName in Notification Center, and the code samples for Threat-Events™ for the running of non-authorized apps shown below.
The specifications and options for Threat-Events™ for the running of non-authorized apps are:
Threat-Event™ Elements | Prevent the running of non-authorized apps Method Detail |
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Appdome Feature Name | App Store Signature Validation |
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 Preventing the running of non-authorized apps Threat-Event™ | |
Threat-Event NAME | This app cannot be installed from unofficial app stores. For your protection, the app will close. Please contact support |
Threat-Event DATA | reasonData |
Threat-Event CODE | reasonCode |
Threat-Event REF | 6902 |
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 |
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 |
timeZone | Time zone |
deviceFaceDown | Is the device face down |
locationLong | Location long |
locationLat | Location lat |
locationState | Location state |
wifiSsid | Wifi SSID |
wifiSsidPermissionStatus | Wifi SSID permission status |
With Threat-Events™ enabled (turned ON), iOS developers can get detailed attack intelligence and granular defense control in iOS applications and create amazing user experiences for all mobile end users when the running of non-authorized apps is detected.
The following is a code sample for native iOS apps, which uses all values in the specification above for App Store Signature Validation:
let center = NotificationCenter.default
center.addObserver(forName: Notification.Name("This app cannot be installed from unofficial app stores. For your protection, the app will close. Please contact support"), object: nil, queue: nil) { (note) in
guard let usrInf = note.userInfo else {
return
}
let message = usrInf["message"]; // Message shown to the user
let reasonData = usrInf["reasonData"]; // Threat detection cause
let reasonCode = usrInf["reasonCode"]; // Event reason code
let currentThreatEventScore = usrInf["currentThreatEventScore"]; // Current threat event score
let threatEventsScore = usrInf["threatEventsScore"]; // Total threat events score
let variable = usrInf["<Context Key>"]; // Any other event specific context key
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
}
[[NSNotificationCenter defaultCenter] addObserverForName: @"This app cannot be installed from unofficial app stores. For your protection, the app will close. Please contact support" object:nil queue:nil usingBlock:^(NSNotification *org_note) {
__block NSNotification *note = org_note;
dispatch_async(dispatch_get_main_queue(), ^(void) {
var threatEventsScore = intent.getStringExtra("threatEventsScore")
NSString *message = [[note userInfo] objectForKey:@"message"]; // Message shown to the user
NSString *reasonData = [[note userInfo] objectForKey:@"reasonData"]; // Threat detection cause
NSString *reasonCode = [[note userInfo] objectForKey:@"reasonCode"]; // Event reason code
NSString *currentThreatEventScore = [[note userInfo] objectForKey:@"currentThreatEventScore"]; // Current threat event score
NSString *threatEventsScore = [[note userInfo] objectForKey:@"threatEventsScore"]; // Total threat events score
NSString *variable = [[note userInfo] objectForKey:@"<Context Key>"]; // Any other event specific context key
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
});
}];
const { ADDevEvents } = NativeModules;
const aDDevEvents = new NativeEventEmitter(ADDevEvents);
function registerToDevEvent(action, callback) {
NativeModules.ADDevEvents.registerForDevEvent(action);
aDDevEvents.addListener(action, callback);
}
export function registerToAllEvents() {
registerToDevEvent(
"This app cannot be installed from unofficial app stores. For your protection, the app will close. Please contact support",
(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
var currentThreatEventScore = userinfo["currentThreatEventScore"] // Current threat event score
var threatEventsScore = userinfo["threatEventsScore"] // Total threat events score
var variable = userinfo["<Context Key>"] // Any other event specific context key
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
);
}
RegisterReceiver(new ThreatEventReceiver(), new IntentFilter("This app cannot be installed from unofficial app stores. For your protection, the app will close. Please contact support"));
class ThreatEventReceiver : BroadcastReceiver
{
public override 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
String currentThreatEventScore = intent.getStringExtra("currentThreatEventScore"); // Current threat event score
String threatEventsScore = intent.getStringExtra("threatEventsScore"); // Total threat events score
String variable = intent.getStringExtra("<Context Key>"); // Any other event specific context key
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
}
}
window.broadcaster.addEventListener("This app cannot be installed from unofficial app stores. For your protection, the app will close. Please contact support", 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
var currentThreatEventScore = userInfo.currentThreatEventScore // Current threat event score
var threatEventsScore = userInfo.threatEventsScore // Total threat events score
var variable = userInfo.<Context Key> // Any other event specific context key
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
});
Prerequisites to Using App Store Signature Validation:
To use Appdome’s mobile app security build system to Prevent the running of non-authorized apps , you’ll need:
- Appdome account (create a free Appdome account here)
- A license for App Store Signature Validation
- Mobile App (.ipa For iOS)
- Signing Credentials (see Signing Secure Android apps and Signing Secure iOS apps)
Using Appdome, there are no development or coding prerequisites to build secured iOS Apps by using App Store Signature Validation. 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 App Store Signature Validation
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.
All apps protected by Appdome are fully compatible with any public app store, including Apple App Store, Google Play, Huawei App Gallery and more.
Features Similar to App Store Signature Validation
Here are a few related resources:
- How to Troubleshoot App Signing in Secured Android & iOS Apps
- Binary Code Obfuscation, Anti-Reversing for Android & iOS Apps
- How to Prevent Code Tampering in Android & iOS Apps
- How to Prevent Code Injection & Process Injection Attacks in Mobile Apps
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.