How to Check for Missing SIM Cards on Android & iOS Devices
Learn to Detect NoSimPresent in Mobile apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.
What Does Detecting Phones Without SIM Cards Reveal?
The ability to recognize when a phone lacks a SIM card unveils critical insights into the device’s operational context and its connectivity capabilities. SIM cards are pivotal for linking devices to cellular networks, thus enabling essential communication functionalities such as calling, texting, and accessing mobile data. The absence of a SIM card signals a disconnection from these cellular services, suggesting that the device might not be actively utilized by an individual for standard communication tasks. This detection is pivotal for applications and services aiming to discern the devices’ operational status, offering a window into whether a device is partaking in regular human activities or possibly serving a different, non-standard purpose.
Why Is Detecting the Absence of SIM Cards Important?
Identifying devices without SIM cards is not merely a technical concern; it is a strategic necessity for safeguarding digital ecosystems and combating fraudulent activities. The importance of this detection lies in several key areas:
- Combating Bot Farms: Bot farms use numerous devices to mimic human activity on digital platforms, aiming to artificially boost engagement or manipulate data. These devices often operate without SIM cards, relying on Wi-Fi for connectivity. Detecting such devices is crucial for identifying and neutralizing bot farm operations.
- Understanding Testing Environments: In software development and testing, devices without SIM cards are commonly employed to evaluate applications or updates in a controlled setting, where cellular connectivity is unnecessary. Recognizing these devices aids in interpreting usage patterns and ensuring services are fine-tuned for genuine user scenarios.
- Preventing Fraud: Devices operating without SIM cards may indicate fraudulent intentions, such as the creation of fake online accounts or engagement in deceptive activities. Early detection of these devices enables proactive measures to prevent fraud and protect online services.
Appdome’s No SIM Present’ feature is designed to detect the absence of a SIM card in a mobile device. It plays a crucial role in scenarios where an application’s functionality or access is restricted based on the presence of a valid SIM card. This feature is particularly relevant for apps that require an added layer of security or need to ensure that the user is operating the device under a standard telecommunication network.
Prerequisites for Using No Sim Present:
To use Appdome’s mobile app security build system to Detect NoSimPresent , you’ll need:
- Appdome account (create a free Appdome account here)
- A license for No Sim Present
- Mobile App (.ipa for iOS, or .apk or .aab for Android)
- Signing Credentials (see Signing Secure Android apps and Signing Secure iOS apps)
Detect NoSimPresent on Mobile apps using Appdome
On Appdome, follow these 3 simple steps to create self-defending Mobile Apps that Detect NoSimPresent 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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No Sim Present 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: No Sim Present.
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Building No Sim Present by using Appdome’s DEV-API:
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Create and name the Fusion Set (security template) that will contain the No Sim Present feature as shown below:
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Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the No Sim Present feature via Appdome Console, to add the No Sim Present 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 No Sim Present 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 No Sim Present feature via Appdome Console
To build the No Sim Present protection by using Appdome Console, follow the instructions below.
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Where: Inside the Appdome Console, go to Build > Geo Compliance Tab > Geo Compliance section.
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When you select the No Sim Present you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains No Sim Present
Figure 4: Fusion Set that displays the newly added No Sim Present protection
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Select the Threat-Event™ in-app mobile Threat Defense and Intelligence policy for No Sim Present:
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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 NoSimPresent.
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Threat-Events™ ON > In-App Detection
When this setting is used, Appdome detects if the mobile device is missing a SIM 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 No Sim Present 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 NoSimPresent (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 No Sim Present 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 No Sim Present protection is now added to the mobile app -
Using Threat-Events™ for NoSimPresent Intelligence and Control in Mobile Apps
Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when NoSimPresent is detected. To consume and use Threat-Events™ for NoSimPresent in Mobile Apps, use AddObserverForName in Notification Center, and the code samples for Threat-Events™ for NoSimPresent shown below.
The specifications and options for Threat-Events™ for NoSimPresent are:
| Threat-Event™ Elements | Detect NoSimPresent Method Detail |
|---|---|
| Appdome Feature Name | No Sim Present |
| 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 NoSimPresent Threat-Event™ | |
| Threat-Event NAME | NoSimPresent |
| 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 | |
|---|---|
| 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 NoSimPresent is detected.
The following is a code sample for native Mobile apps, which uses all values in the specification above for No Sim Present:
x
IntentFilter intentFilter = new IntentFilter();intentFilter.addAction("NoSimPresent");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("NoSimPresent")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("NoSimPresent"), 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: @"NoSimPresent" 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(
"NoSimPresent",
(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("NoSimPresent"));
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)"NoSimPresent", // 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("NoSimPresent", 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...)
});
xxxxxxxxxximport '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 = 'NoSimPresent'; // 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 No Sim Present. 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 No Sim Present
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 Detect SIM Card Swapping in Android & iOS Apps
How to Protect Android & iOS Apps Against Fake GPS Apps
How to Detect Fake Location in iOS Apps
How to Detect Fake Location 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.
