How to Use Frida for Dynamic Analysis and Reverse Engineering for Desktop and Mobile Apps

Published in

Apriorit — Specialized Software Development Company

4 min readDec 15, 2023

Dynamic analysis and reverse engineering allow developers to identify vulnerabilities and discover potential security issues in running applications. There are a lot of ways to implement these two approaches. One of the effective tools that Apriorit experts use to inject code into running applications, analyze apps dynamically, and uncover vulnerabilities is Frida.

In this post we’ve overviewed the main features of Frida. To explore our practical example of using this toolkit, check out the comprehensive article on our blog.

What is dynamic analysis and why is it important?

Dynamic analysis and reverse engineering are two crucial cybersecurity methods that allow businesses to enhance product security. This is effective for:

Vulnerability detection — uncover potential vulnerabilities and plan cybersecurity enhancements to protect your product from data breaches
Real-world simulation — understand how your product will behave in real-world conditions, allowing you to examine your product from the users’ perspective and see how it handles sensitive data and crucial operations
Performance optimization — beyond security, dynamic analysis helps optimize app performance, which can help you improve your product’s user experience and optimize infrastructure costs
Compliance assurance — identify potential breaches before they lead to compliance violations and penalties

Dynamic analysis is used in reverse engineering, which allows developers to dissect software and understand its inner workings even without source code or documentation.

Why to use Frida for Dynamic Analysis?

Frida is a dynamic open-source instrumentation toolkit that allows developers and reverse engineers to inject JavaScript code into running applications. Injection enables developers to trace function calls, modify function behavior, and intercept data in real time, making it an invaluable tool for dynamic analysis.

Frida provides a comprehensive set of APIs that can be used to interact with running applications.

Frida’s architecture is based on a client–server model. The Frida server runs on the target device or computer, while the client is used to interact with the server and inject JavaScript code into running applications.

Dynamic analysis of a desktop application with Frida

Frida supports Windows, macOS, and Linux, making it a reliable choice for analyzing desktop applications regardless of the operating system they run on. There are some of the tasks you can perform with Frida.

Hooking MessageBox in a Windows desktop application
Modifying NSURLRequest in a macOS desktop application

In the full article in our blog, we demonstrate how to use Frida for these tasks and give code example. To read the full material, please, follow the link.

Dynamic analysis of a mobile app with Frida

Dynamic analysis is an effective way to identify vulnerabilities in mobile applications because it allows us to monitor application behavior in real time.

Frida can be used to perform dynamic analysis of both Android and iOS applications. With Frida, we can hook into a running application and monitor its behavior, including function calls, network traffic, and memory use. Frida can be used with unrooted, rooted, and jailbroken devices.

There are some examples of what you can do with Frida to run dynamic analysis on your mobile app:

Bypassing root detection
Tampering with API Calls

To explore our practical example of using Frida in such cases, please, follow the link.

Reverse engineering with Frida

You can use Frida for reverse engineering. It provides a dynamic analysis environment that helps you examine how an application behaves while it’s running. Frida allows us to hook into an application’s execution flow, monitor and manipulate function calls and arguments, and intercept data being sent or received by the application. At Apriorit, we use Frida for a variety of reverse engineering tasks, such as:

Extracting encryption keys
Analyzing network traffic
Tracing system calls
Identifying malware behavior
Researching proprietary protocols
Analyzing binary code

In the full article in our blog, we demonstrate the first three tasks using an Android application as an example. Follow the link to explore the full article.

Final thoughts

Dynamic analysis plays a crucial role in identifying vulnerabilities in applications, as it allows you to look into your software’s inner workings. If you’re looking for ways to protect your web, desktop, or mobile application from security threats, our cybersecurity team will be happy to assist you in creating a bulletproof security strategy and choosing tools that will best suit your needs.