How to Prevent Vishing Fraud in Android & iOS Apps
This Knowledge Base article describes how to use Appdome’s AI/ML in your CI/CD pipeline to continuously deliver plugins that Prevent Vishing Fraud in Mobile apps.
What is Vishing Fraud?
Preventing Vishing fraud focuses on identifying instances where a mobile app is used during an active phone call. While this concurrent use isn’t inherently fraudulent, it becomes significant in certain contexts, particularly during sensitive transactions. For example, if an individual engages in a mobile app activity while on an active call related to a sensitive transaction (such as discussing financial details, making a high-value purchase, or conducting a verification process), this parallel action could raise a security alert. The feature doesn’t automatically assume fraud per se but rather flags such scenarios for additional scrutiny. This is due to the potential risks associated with the simultaneous handling of sensitive activities, which might be indicative of suspicious behavior.
Why Detecting Vishing Fraud is Vital?
While using a mobile app during an active call is not inherently fraudulent, the context and the specific actions being performed simultaneously can raise alerts within fraud detection systems. This is done to protect users and organizations from potential fraudulent activities, identity theft, or security breaches. These alerts trigger further verification steps or investigation to ensure the legitimacy and security of transactions or interactions taking place. This becomes particularly critical when we examine real-world scenarios where such detection capabilities are essential such as:
Fraud Patterns: In some cases, fraudsters may use multiple channels simultaneously to perpetrate fraudulent activities. For example, they might attempt to social engineer a call center representative while using an app to manipulate or access accounts simultaneously. Such simultaneous activities could raise red flags in fraud detection systems.
Anomalous Behavior: Unusual behavior patterns detected by fraud detection systems, such as a sudden change in user behavior (like accessing a banking app during an ongoing call with a customer service representative for an account-related issue), might trigger alerts for potential fraudulent activities.
Risk Mitigation: For security reasons, certain organizations or financial institutions might set policies or algorithms that flag any deviation from standard user behavior, especially during sensitive transactions, to mitigate potential risks associated with fraud or data breaches.
How does Appdome Protect Mobile Apps Against Vishing Fraud?
To protect Android & iOS apps against Vishing Fraud, Appdome implements the following detection methods:
1. App In Use: Detects vishing attempts when the app is actively being used, during incoming calls.
2. App In Foreground: Scans for vishing attempts when the app is open and visible on the screen.
3. User Uses App and Call Together: Detects simultaneous app use and phone calls.
4. User Opens App after Call Starts: Detects if the app is launched after a phone call has begun, for vishing risk assessment.
All these protection measures are designed to provide an extra layer of security, alerting app developers to suspicious calls that could be attempting to steal app users personal details or financial information.”
Prerequisites for Using Appdome's Vishing Fraud Prevention Plugins:
To use Appdome’s mobile app security build system to Prevent Vishing Fraud , you’ll need:
- Appdome account (create a free Appdome account here)
- A license for Vishing Fraud Prevention
- Mobile App (.ipa for iOS, or .apk or .aab for Android)
- Signing Credentials (see Signing Secure Android apps and Signing Secure iOS apps)
How to Implement Prevent Vishing Fraud in Mobile Apps Using Appdome
On Appdome, follow these 3 simple steps to create self-defending Mobile Apps that Prevent Vishing Fraud 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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Mobile App Formats: .ipa for iOS, or .apk or .aab for Android
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Vishing Fraud Prevention is compatible with: Obj-C, Java, JS, C#, C++, Swift, Kotlin, Flutter, React Native, Unity, Xamarin, and more.
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Select the defense: Vishing Fraud Prevention.
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Follow the steps in Sections 2.2-2.2.2 of this article to add the Vishing Fraud Prevention feature to your Fusion Set via the Appdome Console.
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When you select the Vishing Fraud Prevention you'll notice that the Fusion Set you created in step 2.1 now bears the icon of the protection category that contains Vishing Fraud Prevention.
Figure 2: Fusion Set that displays the newly added Vishing Fraud Prevention 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 Vishing Fraud Prevention feature as shown below:Figure 1: Fusion Set that will contain the Vishing Fraud Prevention feature
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Add the Vishing Fraud Prevention feature to your security template.
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Navigate to Build > Anti Fraud tab > Social Engineering Prevention section in the Appdome Console.
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Toggle On > Vishing Fraud Prevention.
(a) Choose to monitor this attack vector by checking the Threat Events checkbox associated with Vishing Fraud Prevention 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 Prevent Vishing Fraud
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 Vishing Fraud Prevention:
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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 Vishing Fraud.
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Threat-Events™ ON > In-App Detection
When this setting is used, Appdome detects if a call is taking place while an application is open on the mobile device 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 Vishing Fraud PreventionPrevent 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 Vishing Fraud (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 Vishing Fraud PreventionPrevent Intelligence and Control in Mobile Apps.
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Configure the User Experience Options for Vishing Fraud Prevention:
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 Vishing Fraud
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Vishing Fraud Prevention Threat Code™. Appdome uses AI/ML to generate a unique code each time Vishing Fraud Prevention 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 Vishing Fraud Prevention protection is now added to the mobile app -
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Certify the Vishing Fraud Prevention feature in Mobile Apps
After building Vishing Fraud Prevention, Appdome generates a Certified Secure™ certificate to guarantee that the Vishing Fraud Prevention protection has been added and is protecting the app. To verify that the Vishing Fraud Prevention 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 Vishing Fraud Prevention has been added to each Mobile app. Certified Secure provides instant and in-line DevSecOps compliance certification that Vishing Fraud Prevention and other mobile app security features are in each build of the mobile app.
Using Threat-Events™ for Vishing Fraud Intelligence and Control in Mobile Apps
Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when Vishing Fraud is detected. To consume and use Threat-Events™ for Vishing Fraud in Mobile Apps, use AddObserverForName in Notification Center, and the code samples for Threat-Events™ for Vishing Fraud shown below.
The specifications and options for Threat-Events™ for Vishing Fraud are:
Threat-Event™ Elements | Prevent Vishing Fraud Method Detail |
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Appdome Feature Name | Vishing Fraud Prevention |
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 Vishing Fraud Threat-Event™ | |
Threat-Event NAME | ActivePhoneCallDetected |
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), 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 Vishing Fraud is detected.
The following is a code sample for native Mobile apps, which uses all values in the specification above for Vishing Fraud Prevention:
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("ActivePhoneCallDetected");
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("ActivePhoneCallDetected")
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)
}
x
let center = NotificationCenter.default
center.addObserver(forName: Notification.Name("ActivePhoneCallDetected"), 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
// Current threat event score
let currentThreatEventScore = usrInf["currentThreatEventScore"];
// Total threat events score
let threatEventsScore = usrInf["threatEventsScore"];
// Replace '<Context Key>' with your specific event context key
// let variable = usrInf["<Context Key>"];
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
}
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[[NSNotificationCenter defaultCenter] addObserverForName: @"ActivePhoneCallDetected" object:nil queue:nil usingBlock:^(NSNotification *org_note) {
__block NSNotification *note = org_note;
dispatch_async(dispatch_get_main_queue(), ^(void) {
// Message shown to the user
NSString *message = [[note userInfo] objectForKey:@"message"];
// Threat detection cause
NSString *reasonData = [[note userInfo] objectForKey:@"reasonData"];
// Event reason code
NSString *reasonCode = [[note userInfo] objectForKey:@"reasonCode"];
// Current threat event score
NSString *currentThreatEventScore = [[note userInfo] objectForKey:@"currentThreatEventScore"];
// Total threat events score
NSString *threatEventsScore = [[note userInfo] objectForKey:@"threatEventsScore"];
// Replace '<Context Key>' with your specific event context key
// NSString *variable = [[note userInfo] objectForKey:@"<Context Key>"];
// Your logic goes here (Send data to Splunk/Dynatrace/Show Popup...)
});
}];
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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(
"ActivePhoneCallDetected",
(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("ActivePhoneCallDetected"));
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)"ActivePhoneCallDetected", // 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("ActivePhoneCallDetected", 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 = "ActivePhoneCallDetected";
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 Mobile Apps by using Vishing Fraud Prevention. 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 Vishing Fraud Prevention
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 Team Viewer & Remote Desktop Exploits in iOS Apps
- How to Detect SIM Card Swapping in Android & iOS Apps
- How to Block Remote Desktop Exploits in Android Apps
- How to Detect Fake Location in Android Apps
- How to Implement VPN Detection for Android & iOS Apps
- How to Detect Fake GPS Location Inside Android & iOS 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.