Exploring Reverse Engineering: Benefits, Misuse, and the Role of Application Hardening

Originally Published on June 16, 2023 — Updated on March 20, 2024

Simply put, (software) reverse engineering analyzes software to unravel its inner workings, allowing us to gain valuable insights into its functionality and design. In this blog post, we’ll explore the world of reverse engineering. We’ll discuss when reverse engineering proves beneficial, its potential misuse, the frequency of its occurrence, and the role of application hardening in making reverse engineering more challenging for threat actors.¹

What is Reverse Engineering?

Reverse engineering is the art of dissecting a system or component to understand its structure, behavior, and purpose. It involves carefully analyzing the software through various techniques to gain insights into how the software functions. Reverse engineering can be likened to taking apart a complex puzzle to comprehend its intricate mechanisms. This process allows us to understand the software at a deeper level in order to understand what the software does and how it does it.

The journey into software reverse engineering begins with understanding its foundational principles. It involves taking a compiled application and deconstructing it to its constituent code to understand its inner workings. The goal of reverse engineering is to reveal the logic, features, and functionalities embedded within the software. Practitioners use various tools and techniques, such as disassemblers and decompilers, to translate binary code back into a form that is closer to human-readable source code. This process not only unveils the software’s architecture but also exposes any underlying secrets it might contain. The essence of reverse engineering lies in its ability to demystify the software, offering insights into its construction and operation that are not readily apparent from its surface.

Code Recognition and Data Patterns

One of the pivotal aspects of reverse engineering is the ability to recognize code structures and data patterns within a sea of binary information. This skill is paramount for reverse engineers as it allows them to identify significant segments of code, understand how data is processed, and predict the software’s behavior under various conditions. Tools equipped with pattern recognition capabilities greatly aid in this endeavor, allowing for the identification of common algorithms, cryptographic functions, and data structures. By discerning these patterns, reverse engineers can piece together how the application manages data flow, processes inputs, and executes operations. This understanding is crucial for modifying software behavior, enhancing functionality, or – crucially in this context – understanding how a client app communicates with a server in order to exploit those communication channels for the purpose of stealing data or IP.

Debugging

Debugging is an integral part of the reverse engineering process, offering a window into the software’s runtime behavior. Through debugging, reverse engineers can step through the software’s execution, inspecting variables, and understanding decision-making processes in real-time. This hands-on exploration is critical for identifying discrepancies between expected and actual software behavior, revealing bugs, or understanding complex algorithms. Debugging tools enable reverse engineers to set breakpoints, examine memory states, and modify execution flow, providing a powerful means to dissect software. Through diligent debugging, reverse engineers can uncover hidden functionalities, security vulnerabilities, and even undocumented features, further enriching their comprehension of the software’s inner mechanisms.

When is Reverse Engineering Good?

People who code like to reverse engineer software because it helps them understand how the software works. Reverse engineering is an essential process in learning to write code and develop applications. As such, there are hundreds of resources to help aspiring computer scientists reverse engineer source code and applications, including How-To guides, tutorials, and countless tools including IDAPro, FRIDA, and numerous debuggers. None of these tools are bad/wrong/illegal and most are accessible within Github, Gitlab, and in various Reddit forums.

Reverse engineering also plays a pivotal role in other areas of computer science. One prominent example is malware research. Malware analysts employ reverse engineering techniques to analyze malicious software, understand its behavior, and develop effective countermeasures. Analysts can identify their infection vectors, functionality, and potential impact on targeted systems by dissecting malware samples. This knowledge aids in developing robust antivirus signatures/heuristics and security solutions to protect against such threats.

Vulnerability research is another area where reverse engineering proves invaluable. Security researchers use reverse engineering to identify and understand vulnerabilities in software or systems. Researchers can pinpoint weak points that threat actors could exploit by analyzing the software’s underlying code. This enables the development of patches and security updates to address these vulnerabilities and/or recommendations for obfuscations that hide secret calls and functions, thus strengthening the overall security posture of the company releasing the software or the app that contains the software.

Reverse engineering also aids in security assessments. By analyzing the code and structure of an application or system, security professionals can assess its robustness and identify potential weaknesses. This analysis examines cryptographic algorithms, authentication mechanisms, and access controls, among other elements. The insights gained from reverse engineering assist in refining security measures – including (again) recommendations for obfuscations and anti-tamper measures and ensuring the overall integrity of the system.

When is Reverse Engineering Bad?

While reverse engineering has numerous legitimate applications, it can also be misused for malicious purposes. One example is when individuals employ reverse engineering techniques to violate intellectual property (IP) and copyright laws. Reverse engineering can enable unauthorized access to proprietary software or the replication of patented technology, leading to significant financial losses for innovators and copyright holders.

Another concerning misuse of reverse engineering is when threat actors employ it to discover the inner workings of software systems and access back-end systems without proper authorization. By reverse engineering a software application, a threat actor can identify how a client application access server data and use that information to access server data themselves.

Frequency of Reverse Engineering

Reverse engineering occurs more frequently than we might realize. Over a four week period in February of 2022, for example, we found that 57% of the applications we monitored were run at least once in an environment that facilitates reverse engineering. In many of those instances, modified code was used alongside reverse engineering techniques, further underscoring the need for robust security measures.

Application Hardening and Reverse Engineering

To counteract the risks associated with reverse engineering, organizations employ various techniques collectively known as application hardening. Application hardening involves implementing measures that make it more challenging for potential threat actors to reverse engineer software or gain unauthorized access to critical systems.

Code obfuscation is a common approach employed in application hardening. It involves transforming the source code into a more complex and convoluted form, making it difficult for reverse engineers to understand its logic and functionality. Organizations can protect their intellectual property and deter reverse engineering attempts by obfuscating the code.

Anti-tamper mechanisms are another essential aspect of application hardening. These mechanisms incorporate security measures into the software to detect and respond to tampering attempts. They can include integrity checks, code signing, self-protection techniques as well as many other tactics. By implementing anti-tamper mechanisms, organizations can enhance the resistance of their software against reverse engineering attacks.

Furthermore, white-box cryptography is an approach that combines cryptographic algorithms with obfuscation techniques. It further protects sensitive data within the application by embedding encryption keys and cryptographic operations directly into the code. This approach ensures that even if the software is reverse engineered, it becomes significantly challenging for threat actors to extract the cryptographic keys or understand the encryption mechanisms in use.

Runtime application self-protection (RASP) is also associated with the practice of application hardening. RASP incorporates security controls directly into the application’s runtime environment, allowing it to detect and respond to potential attacks or unauthorized activities. By dynamically monitoring the application’s behavior, RASP can identify and mitigate security threats, including those originating from reverse engineering attempts.

Conclusion

Reverse engineering is a powerful tool in the arsenal of computer scientists and security professionals. Its applications range from malware analysis and vulnerability research to security assessments. However, reverse engineering is also a practice used by threat actors wishing to steal intellectual property theft access to critical systems.

Organizations employ application hardening techniques to mitigate the risk threat actors who use reverse engineering to achieve ill-gotten gains. Code obfuscation, anti-tamper mechanisms, white box cryptography, RASP, and software watermarking are some of the methods used to protect software and discourage reverse engineering attempts.

By understanding the intricacies of reverse engineering and implementing comprehensive security strategies, we can safeguard our software, protect intellectual property, and ensure the integrity of applications in the ever-evolving digital landscape.

To learn more about how threat actors reverse engineer unsecured software and how a Protection Blueprint can provide Application Security and change the tide, check out our webinar: See How Threat Actors Reverse Engineer Applications – and How to Protect Against It