Reverse Engineering Techniques for Penetration Testers
Penetration testing is an in-demand professional skill in today’s cybersecurity market. Data breaches cost businesses $4.2 million in 2021 (IBM, 2021), and penetration testers can help businesses protect and secure some of their most valuable assets.
In a survey by the World Economic Forum (2022), 50% of leaders said responding to security threats would be difficult due to talent shortages. This means that there are huge opportunities in cybersecurity for anyone who wants to advance their career. In this guide, we’ll explain why reverse engineering methods and tools are an important part of a cybersecurity professional’s skill set.
Common Reverse Engineering Methods
Finding vulnerabilities in software is complex and the difficulty increases with the size of the code base. To locate problems, testers rarely rely on a single method, instead using a variety of penetration testing techniques, including reverse engineering.
Reverse engineering analysis generally falls into two categories: static and dynamic. Many cybersecurity professionals use a combination of the methods and tools described below to find vulnerabilities.
Static analysis debugs compiled code without actually running the application. In this process, testers use static code analyzers: software that examines code to look for weaknesses that can lead to security incidents. These tools can detect issues such as SQL injection and cross-site scripting (XSS) vulnerabilities. Static analysis can be divided into two categories: source code analysis and binary code analysis.
How do static code analysis tools work?
Static analysis tools can evaluate compiled code before it is run, including source code and binary code.
- Source code analysis: This technique examines the source code to identify areas where there are vulnerabilities that an attacker could exploit. Source code analyzers can find buffer overruns, vulnerabilities to format string attacks, invalid pointer dereferences, and more. Static analyzers can be used to find vulnerabilities in client-side and server-side applications.
- Binary code analysis: This method involves analyzing the binary code of software using a hex editor, which displays all characters as hexadecimal numbers. This is then converted into machine code that can be read and analyzed for patterns or keys that can help uncover weaknesses in an application’s programming logic.
Common reverse engineering tools for static analysis include:
- Static Analysis Tool for Java (SATJ): This tool can be used to find defects in Java source code.
- PVS-Studio: PVS-Studio integrates with several popular integrated development environments (IDEs), including Microsoft Visual Studio and Eclipse. The tool includes a C/C++ syntax checker, an IDA Pro plugin, and integration with the Viva64 decompiler.
Dynamic scanning is an automated approach that walks through all of a program’s execution paths to identify vulnerabilities. Dynamic analysis tests all possible paths of an application, as well as the behavior of each path, and finds vulnerabilities using predefined rules.
- Automated fingerprinting: Automated fingerprinting is a technique for identifying malicious code using heuristics to find commonalities, for example, applying a pattern to find exploits in C++ to Java or another language programming. The idea is to create a “fingerprint” for each language, which can be thought of as a template that can be used to apply the same model to identify malicious code in multiple programming languages.
- Preprocessor injection: The idea behind preprocessor injection is to inject shellcode into a program before it is compiled and executed. Then when the program is executed, it executes shellcode instead of real code. This technique exploits a flaw in the way some programs handle their command-line arguments.
- Symbol resolution: Symbol solving involves finding functions in binaries and binding them to their correct symbols. This is useful because it helps identify unused functions in the binary.
Common engineering tools for dynamic analysis include:
JavaBeacon (JBeacon): This Java-based dynamic analysis tool can be used for static and dynamic analysis of Java applications.
Kali Linux: Kali is an open-source Linux distribution designed for penetration testing that includes several tools for static and dynamic application security testing, including:
- WHOIS search
Why should you get a penetration testing certification?
Penetration testing is a lucrative career. According to ZipRecruiter (2022), the average annual salary for a penetration tester in the United States is $116,323. In addition to a solid understanding of IT fundamentals and testing strategies, such as reverse engineering, penetration testers also typically need knowledge and skills in the following areas:
- Network and application security
- Programming, especially scripting languages (eg Python, Bash, Java, Ruby, Perl)
- Threat modeling
- Working comfort in Linux, Windows and macOS environments
- Knowledge of security assessment tools
The best way to start or advance your penetration testing career is to take training and get certified. EC-Council’s Certified Penetration Testing Professional (C|PENT) certification is designed to equip you with expertise in the tools and techniques used in this rewarding field. Join today to start your path to a cybersecurity career.