How to Prevent Dynamic Hooking of iOS Apps

Learn to Prevent Hooking and Hooking Frameworks in iOS apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.

What is Hooking?

A hook is a means of executing custom code (function) either before, after, or instead of existing code. For example, a function may be written to “hook” into the login process of a mobile application and alter the authentication workflow, by requesting users to enter their social security number or re-type their password. Fraudsters use dynamic instrumentation toolkits such as Frida to hook into the application, interact with the running processes, and inject their own JavaScript code, thus replacing the original code.

How does Appdome Prevent Hooking of iOS Apps?

Appdome’s Prevent Hooking Frameworks feature detects and prevents common hooking methods and frameworks that attempt to intercept function/method calls, messages, or API calls and then modify their instructions or output. Appdome also detects any code injected into the app’s process memory and prevents it from running.

Prevent Hooking and Hooking Frameworks on iOS apps using Appdome

On Appdome, follow these simple steps to create self-defending iOS Apps that Prevent Hooking and Hooking Frameworks without an SDK or gateway:

1. Upload the Mobile App to Appdome.

   1. Upload an app to Appdome’s Mobile App Security Build System

   2. Upload Method: Appdome Console or DEV-API
   3. iOS Formats: .ipa
   4. Prevent Hooking and Hooking Frameworks Compatible With: Obj-C, C+, Java, Swift, Flutter, React Native, Unity, Xamarin, Cordova and more

2. Build the feature: Prevent Hooking and Hooking Frameworks.

   1. Building Prevent Hooking and Hooking Frameworks by using Appdome’s DEV-API:

      1. Create and name the Fusion Set (security template) that will contain the Prevent Hooking and Hooking Frameworks feature as shown below:
      

      Figure 1: Fusion Set that will contain the Prevent Hooking and Hooking Frameworks feature
      Note: Naming the Fusion Set to correspond to the protection(s) selected is for illustration purposes only (not required).

      2. Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the Prevent Hooking and Hooking Frameworks feature via Appdome Console, to add the Prevent Hooking and Hooking Frameworks feature to this Fusion Set.

      3. 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).

      4. 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:

         1. Build an API for the app – for instructions, see the tasks under Appdome API Reference Guide
         2. Look for sample APIs in Appdome’s GitHub Repository

   2. Building the Prevent Hooking and Hooking Frameworks feature via Appdome Console

      To build the Prevent Hooking and Hooking Frameworks protection by using Appdome Console, follow the instructions below.

      1. Where: Inside the Appdome Console, go to Build > Anti Fraud Tab > Mobile Cheat Prevention section
      2. How: Check whether Prevent Code Injection is toggled On (enabled), otherwise enable it . You can see that the feature Prevent Hooking and Hooking Frameworks is enabled by default, as shown below.

         Figure 3: Prevent Hooking and Hooking Frameworks 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.

      3. When you enable Prevent Code Injection you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains Prevent Hooking and Hooking Frameworks

         

         Figure 4: Fusion Set that displays the newly added Prevent Hooking and Hooking Frameworks protection

      4. Click Build My App at the bottom of the Build Workflow (shown in Figure 3).

   Congratulations!  The Prevent Hooking and Hooking Frameworks protection is now added to the mobile app

3. Certify the Prevent Hooking and Hooking Frameworks feature in iOS Apps.

   After building Prevent Hooking and Hooking Frameworks, Appdome generates a Certified Secure™ certificate to guarantee that the Prevent Hooking and Hooking Frameworks protection has been added and is protecting the app. To verify that the Prevent Hooking and Hooking Frameworks 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 Prevent Hooking and Hooking Frameworks has been added to each iOS app. Certified Secure provides instant and in-line DevSecOps compliance certification that Prevent Hooking and Hooking Frameworks and other mobile app security features are in each build of the mobile app