Thick client applications are vastly in use these days. Their increasing popularity is the main reason they have become a lucrative target for hackers. However, thick client pentesting can help you fortify the security of these applications. But 100% immunity of your applications to cyber threats is something that no one will promise you.
Thick client applications are easily stored on your device’s local storage. Be it your desktop, laptop, or mobile device, these apps, unlike web applications, can run without an internet connection. Some common examples of thick client applications are computer games like Call of Duty and Uncharted. Web browsers, music players, and video and chat tools like Teams, Zoom, Slack, etc. are also among the most widely used thick client applications.
Hackers do target these applications due to the heavy load of user data available on them for loot. Penetration testing on a regular basis is the best way to secure these applications from prevailing cyber threats. Going further in the blog we will know about the tools and techniques for thick client penetration testing. Let us start with the tools…
Top Thick Client Pentesting Tools 
There are quite a few tools available out there in the market for security testing of thick clients. The following are the best among them:
1. Echo Mirage
This is an efficient testing solution for DLL injection and function hooking techniques. Echo Mirage can help you intercept the traffic received by the local application. It allows you to intercept the application’s traffic in real-time or manipulate it both ways.
There are two modes to execute the Echo Mirage testing tool:
- You can launch an executable file from ECHO: in this process, we give the applications to the Echo Mirage penetration testing tool. Then the pen testing tool selectively launches the application to be tested.
- You can inject Echo Mirage into a running process: In this method of execution, the tool injects the process by hooking. Then it selects the thick client application for testing from the multiple running processes.
It is an intercepting proxy server that allows you to determine the cyber resilience of web-based applications against evolving threats. This tool allows you to intercept the request of other thick client penetration testing. Plus, you can use BURP as the invisible mode without letting anyone on the outside know about it. There are quite a few advantages of using BURP as a tool for thick client application security testing. For instance, you can easily test a desktop or thick client component that runs outside the browser.
Wireshark is the most popular and widely used tool in the world to perform the analysis of network protocols. With the help of this tool, you can capture network packets and view them in detail. Real-time analysis of these data packets allows you to take a close look at your network traffic. Through this detailed analysis, you can easily understand the root cause of problems you are facing on your network front. Applying this strategy to thick client applications can help you identify server-side threats and mitigate them.
Putty is basically an automated and open-source SSH client. You can use it to connect with the server. This tool can also serve you as a software terminal emulator in windows and Linux-based systems.
All these tools are pretty efficient in testing the security functionalities of a thick client application. Now let us discuss the technique involved in thick client penetration testing.
Approach for Thick Client Pentesting 
Thick client applications by default are much more complex and sophisticated in comparison to mobile or web-based applications. Hence, you need a comprehensive approach for executing penetration testing on such applications. There is a need to adopt a specific approach for thick client penetration testing. The following are key points to remember while carrying out pen testing on thick client applications:
- Identify and gather information on the technology stack used on both the client and the server sides of the thick client application.
- Try to know everything about the application’s functionality and behavior before executing the penetration test.
- Recognize and mark all different entry points available within the application for user input.
- Learn about the core security mechanisms used in the application to stay safe from attacks.
- Try to identify the common and typical weak points and vulnerabilities such as languages and frameworks.
Although thick client pentesting is a tricky task to carry out with precision. But the modern tools and techniques make it easier for the testing teams.