How to Detect SIM Card Swapping in Android & iOS Apps
Learn to Detect SimStateInfo in Mobile apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.
What is a SIM Swap Attack?
A SIM swap attack is a form of identity theft where cybercriminals trick a cellular service provider into transferring a victim’s service to a SIM card under their control. This allows the attacker to hijack the victim’s phone number and intercept texts and calls, including crucial password recovery and account verification codes. The primary objective of SIM swapping is to exploit two-factor authentication to gain unauthorized access to sensitive accounts like banking or social media.
Why Detecting SIM Card Swapping is Vital ?
Each SIM card has a unique identifier, which mobile networks use to deliver services and communications to the correct device. In a SIM swap scenario, the victim’s cellular account gets linked to a different SIM card, diverting all incoming network traffic to the attacker. This kind of attack is a significant threat because it can bypass two-factor authentication, rendering standard security measures ineffective. Appdome’s ‘Detect SIM Swap’ feature is designed to detect the presence of a SIM swap within a mobile application and send a threat event notification to the app developer. This early detection is fundamental in enabling a prompt response to potential security breaches. This is especially important for apps that handle financial transactions or personal data, where the consequences of unauthorized access can be severe. Detecting SIM swaps in real time helps maintain the integrity of the user’s mobile experience and trust in the application’s security protocols.
Note: If you receive the following message, please ensure that your app is running on the correct Appdome engine version.
Prerequisites for Using Detect SIM Swap:
To use Appdome’s mobile app security build system to Detect SimStateInfo , you’ll need:
- Appdome account (create a free Appdome account here)
- A license for Detect SIM Swap
- Mobile App (.ipa for iOS, or .apk or .aab for Android)
- Signing Credentials (see Signing Secure Android apps and Signing Secure iOS apps)
Detect SimStateInfo on Mobile apps using Appdome
On Appdome, follow these 3 simple steps to create self-defending Mobile Apps that Detect SimStateInfo 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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Mobile App Formats: .ipa for iOS, or .apk or .aab for Android
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Detect SIM Swap Compatible With: Obj-C, C+, Java, JS, C#, C++, Swift, Kotlin, Flutter, React Native, Unity, Xamarin, and more
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Build the feature: Detect SIM Swap.
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Building Detect SIM Swap by using Appdome’s DEV-API:
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Create and name the Fusion Set (security template) that will contain the Detect SIM Swap feature as shown below:
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Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the Detect SIM Swap feature via Appdome Console, to add the Detect SIM Swap 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 Detect SIM Swap 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 Detect SIM Swap feature via Appdome Console
To build the Detect SIM Swap protection by using Appdome Console, follow the instructions below.
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Where: Inside the Appdome Console, go to Build > Anti Fraud Tab > Social Engineering Prevention section.
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When you select the Detect SIM Swap you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains Detect SIM Swap
Figure 4: Fusion Set that displays the newly added Detect SIM Swap protection
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Select the Threat-Event™ in-app mobile Threat Defense and Intelligence policy for Detect SIM Swap:
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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 Detect SimStateInfo.
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Threat-Events™ ON > In-App Detection
When this setting is used, Appdome detects the presence of SIM card swapping 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 Detect SIM Swap 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 SimStateInfo (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 Detect SIM Swap 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 Detect SIM Swap protection is now added to the mobile app -
Using Threat-Events™ for SimStateInfo Intelligence and Control in Mobile Apps
Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when SimStateInfo is detected. To consume and use Threat-Events™ for SimStateInfo in Mobile Apps, use AddObserverForName in Notification Center, and the code samples for Threat-Events™ for SimStateInfo shown below.
The specifications and options for Threat-Events™ for SimStateInfo are:
Threat-Event™ Elements | Detect SimStateInfo Method Detail |
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Appdome Feature Name | Detect SIM Swap |
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 SimStateInfo Threat-Event™ | |
Threat-Event NAME | SimStateInfo |
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 |
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 |
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 SimStateInfo is detected.
The following is a code sample for native Mobile apps, which uses all values in the specification above for Detect SIM Swap:
x
IntentFilter intentFilter = new IntentFilter();
intentFilter.addAction("SimStateInfo");
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
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...)
}
};
​
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
registerReceiver(threatEventReceiver, intentFilter, Context.RECEIVER_NOT_EXPORTED);
} else {
registerReceiver(threatEventReceiver, intentFilter);
}
x
val intentFilter = IntentFilter()
intentFilter.addAction("SimStateInfo")
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
var currentThreatEventScore = intent?.getStringExtra("currentThreatEventScore") // Current threat event score
var threatEventsScore = intent?.getStringExtra("threatEventsScore") // Total threat events score
var variable = intent?.getStringExtra("<Context Key>") // Any other event specific 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)
}
let center = NotificationCenter.default
center.addObserver(forName: Notification.Name("SimStateInfo"), 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: @"SimStateInfo" object:nil queue:nil usingBlock:^(NSNotification *org_note) {
__block NSNotification *note = org_note;
dispatch_async(dispatch_get_main_queue(), ^(void) {
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(
"SimStateInfo",
(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("SimStateInfo"));
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...)
}
}
NSNotificationCenter.DefaultCenter.AddObserver(
(NSString)"SimStateInfo", // Threat-Event Identifier
delegate (NSNotification notification)
{
var message = notification.UserInfo.ObjectForKey("message"); // Message shown to the user
var reasonData = notification.UserInfo.ObjectForKey("reasonData"); // Threat detection cause
var reasonCode = notification.UserInfo.ObjectForKey("reasonCode"); // Event reason code
var currentThreatEventScore = notification.UserInfo.ObjectForKey("currentThreatEventScore"); // Current threat event score
var threatEventsScore = notification.UserInfo.ObjectForKey("threatEventsScore"); // Total threat events score
var variable = notification.UserInfo.ObjectForKey("<Context Keys>"); // Any other event specific context key
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
});
window.broadcaster.addEventListener("SimStateInfo", 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...)
});
xxxxxxxxxx
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> {
static const String _eventChannelName = 'SimStateInfo'; // Replace with your EventChannel name
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
String currentThreatEventScore = eventData['currentThreatEventScore']; // Current threat event score
String threatEventsScore = eventData['threatEventsScore']; // Total threat events score
​
// Any other event specific context key
String variable = eventData['<Context Key>'];
});
}
​
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
}
Using Appdome, there are no development or coding prerequisites to build secured Mobile Apps by using Detect SIM Swap. 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 SIM Swap
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 Prevent Social Engineering Attacks in Android & iOS Apps
How to Prevent Vishing Fraud in Android & iOS Apps
How to Block Remote Desktop Exploits in iOS Apps
How to Block Remote Desktop Exploits in Android 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.