Reverse Engineering in Cybersecurity

Published on: January 10, 2023

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20 min read

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For German Version

The process of deconstructing software, machinery, airplanes, architectural structures, and other goods in order to get design knowledge is known as reverse engineering, often referred to as back engineering. Reverse engineering frequently entails dismantling smaller parts of bigger items. You may replicate a part by using the reverse engineering approach to learn how it was created. When buying a replacement item from an original equipment manufacturer (OEM) is not an option, businesses frequently employ this strategy.

In this article we will discuss the following topics regarding reverse engineering:

• What is reverse engineering?

• What are examples of reverse engineering?

• What is the purpose of Reverse Engineering

• What are the stages of reverse engineering?

• What are the benefits of reverse engineering?

• What are the best reverse engineering tools?

• Is reverse engineering illegal?

• Why is reverse engineering unethical?

What is Reverse Engineering?

Reverse engineering is the process of evaluating the functionalities and information flow of a program or hardware in order to comprehend its functioning and behavior. It is done mostly to learn how something works and to analyze it, although it is frequently used to reproduce or improve the item. Reverse-engineering is a widespread practice in cyber defense to analyze malware. Software, physical devices, military technologies, and even biological processes including gene function can all be reverse-engineered.

Reverse engineering is a technique that has been used for decades in fields other than computers. The machine code of a program, or the string of 0s and 1s transmitted to the logic processor, is the subject of software reverse engineering. To convert the machine code back into the original source code, program language statements are employed.

Reverse engineering is used to teach someone how something works, repurpose outmoded goods, do a security study, obtain a competitive advantage, or any number of other things, depending on the technology. Reverse engineering is the process of extracting information from a final product, regardless of how the knowledge is used or what it pertains to.

What are Examples of Reverse Engineering?

Reverse engineering differs based on what it is used for and why the technology is being reverse-engineered. Reverse engineering plays a crucial role in a wide range of sectors, including military applications, software development, and mechanical engineering. Common examples of reverse engineering are as follows:

• Software: Reverse engineering has been used to dismantle software in several situations. A typical illustration is converting a program created for one CPU to another. Other instances include rebuilding missing source code, researching how a program executes specific actions, enhancing performance, and repairing flaws or resolving mistakes when the source code is unavailable. For instance, the basic input/output system (BIOS) software developed by Phoenix, a U.S. software business, was compatible with IBM's exclusive version. Phoenix did this by documenting the steps it took without referencing the proprietary code, reverse engineering the IBM version in a way that shielded them from copyright claims.

  The application of software reverse engineering extends to malware. Obfuscating software code is a common tactic used by threat actors to prevent their malicious code from being found or understood. Reverse engineering is used by the proprietors of affected software or systems to find harmful material, such as a virus. In order to develop its own offensive cyberweapons, the U.S. Defense Intelligence Agency has stated that it plans to employ these techniques to reverse-engineer opponent software. The National Security Agency's Ghidra software, for example, is used to reverse-engineer the WannaCry ransomware, and other tools are available to assist in this process.

• PC Components: A processor maker can purchase a competitor's CPU, reverse engineer it, and then utilize what it discovers to create its own processor if it wants to learn how that competitor's processor operates. This procedure costs a lot of money, needs a lot of knowledge, and is prohibited in many nations. When the original components for old equipment are no longer readily available, reverse engineering is frequently employed to produce replacement parts. To improve security, computer components are reverse-engineered. For instance, Google's Project Zero used reverse engineering to find microprocessor vulnerabilities.

• Network Security Evaluations: Reverse engineering is a technology used by companies doing network security evaluations. Their security staff is divided into two squads. The first team simulates assaults, while the second team keeps an eye on the network and analyzes the other team's attacks. The corporate network is strengthened using the information learned from these fictitious assaults.

• Mechanical Engineering: Reverse engineering is a useful method for comprehending the internal mechanisms and determining the underlying cause of failure or breakdown in a mechanical item. Through meticulous disassembly and thorough analysis of each constituent, engineers may get a comprehensive understanding of the appliance's design and manufacturing process. This understanding enables them to accurately identify any flaws or imperfections that may have had a role in the incident.

  Reverse engineering is essential for guaranteeing the safety and dependability of a product. Through the process of reverse engineering, engineers have the ability to discover any design deficiencies in defective equipment, which may result in accidents or malfunctions.

• Medicine Applications: Through the process of reverse engineering, scientists may analyze the complicated relationships between genes to understand the complex systems that cause illnesses. This allows them to find prospective targets for treatment. Reverse engineering enables researchers to understand the interplay between genes and the impact of these interactions on diverse biological processes. Scientists may acquire valuable knowledge about the development of diseases and the effects of drugs, and they can even make predictions about the results for patients. This understanding facilitates the development of medicines that specifically target certain conditions or diseases.

• Military Applications: Through the process of reverse engineering confiscated equipment or weapons, military forces may acquire important knowledge about their adversary's capabilities and enhance their defensive plans. Reverse engineering allows military professionals to evaluate and comprehend the functioning of hostile technology. This enables them to discern vulnerabilities and weaknesses that may be used during military operations or employed to devise countermeasures.

What are Reverse Engineering Attack Examples?

In this section, we will provide 3 reverse engineering attack scenarios:

1. Source Code Analysis: Let's examine an Android application designed for financial purposes. The APK file may be readily extracted using 7zip, Winrar, WinZip, or Gunzip. After being extracted, the attacker has the manifest file, assets, resources, and most significantly, the classes.dex file.

   By using a Dex to Jar converter, an assailant may effortlessly transform it into a jar file. Next, the Java Decompiler, such as JDgui, will generate the code for you.

2. String Table Analysis: The attacker executes the 'strings' command on the unencrypted application. Through the investigation of the string table, the attacker uncovers a fixed connection string that includes login credentials for a backend database. The attacker utilizes those credentials to get entry into the database. The attacker illicitly acquires a wide range of personally identifiable information (PII) pertaining to the application's users.

3. Cross-Functional Analysis: The assailant used IDA Pro to target an app that lacks encryption. Through the study of the string table and functional cross-referencing, the attacker identifies the presence of Jailbreak detecting code. The assailant utilizes this information in a subsequent code-modification assault to render jailbreak detection inoperable inside the mobile application. Subsequently, the assailant proceeds to implement a modified version of the application that utilizes method swizzling in order to illicitly acquire consumer data.

What is the Purpose of Reverse Engineering?

Learning how a system or thing functions is the goal of reverse engineering. Numerous justifications exist for doing this. Reverse engineering is a technique used to discover how something operates and then replicate it or produce a comparable entity with improved features.

Reverse engineering software or hardware frequently aims to find a cheaper way to make a similar product or is done since the original product is no longer being produced. In the field of information technology, reverse engineering is used to solve compatibility problems and make the hardware or software operate with other hardware, software, or operating systems that it wasn't designed to.

An excellent example is Apple's Logic Pro software, which enables artists to write, record, arrange, edit, and mix music. Only Mac computers can run Logic Pro, and it is not a cheap program. The curriculum includes a number of exclusive digital tools. A programmer learns how to reverse-engineer such digital instruments, find out how they function and alter them to operate with Logic Pro or to be compatible with other Windows-compatible music applications.

What are the Stages of Reverse Engineering?

The technique of reverse engineering is unique to the thing being worked on. There are three general processes that any reverse-engineering endeavor must follow, regardless of the situation. The stages of reverse engineering are explained below::

1. Extraction of Information: In order to reverse-engineer an object, information regarding its design must first be analyzed, retrieved, and then inspected to ascertain how the parts fit together. This could involve obtaining the source code and relevant design documentation for analysis in software reverse engineering. Additionally, using tools like a disassembler to separate the software into its component pieces is necessary.

2. Modeling: The gathered data is abstracted into a conceptual model, each component of which explains its role in the wider framework. Taking information unique to the original and abstracting it into a generic model that can be used to direct the creation of other things or systems is the goal of this stage. An example of this in software reverse engineering is a data flow diagram or a structure chart.

3. Review: To check that the model is a realistic abstraction of the underlying item or system, evaluate it and test it in various circumstances. Software testing is used to accomplish this in software engineering. The model is used to redesign the original thing after it has been tested.

Reverse engineering software requires the use of a number of tools. Hexadecimal dumpers are tools that publish or display binary numbers from programs in hexadecimal. Reverse engineers can locate specific sections of a program and determine how they operate by understanding the bit patterns that indicate the processor instructions and the durations of the instructions.

The disassembler is another tool for software reverse engineering. Each executable instruction is shown as text once the binary code has been read. A debugger is used to stop a disassembler from deconstructing the data parts of a program because a disassembler cannot discern the difference between an executable instruction and the data the program requires. A computer cracker might use these tools to access a computer system or do other harm by using them.

When the original blueprint is no longer accessible, a manufactured item can be recreated using computer-aided design (CAD). In order for the component to be remanufactured, 3D scans of the part must be created. The part is measured using coordinate measuring equipment, and as it is being measured, CAD software creates a 3D wireframe picture that is presented on a monitor. The wireframe picture is dimensioned when the measuring is finished. These techniques allow for the reverse engineering of any component.

What are the Benefits of Reverse Engineering?

The engineering sector is flexible and innovative. Today's engineers use innovation and creativity to create new products that serve their consumers. These engineering innovations are crucial for streamlining business transactions and enhancing the local economy. However, one question comes to mind when you consider innovation. How can engineers of today maintain innovation in a hectic commercial environment?

In reverse engineering, the solution is found. Innovating and igniting ideas that fill needs in many industry sectors is made possible in large part through reverse engineering. Reverse engineering, at its core, is the act of removing components from damaged items in order to assess how well each component functions before implementing the findings into new products. Some advantages of reverse engineering are examined below:

• Examine current strategies and designs: Reverse engineering allows you to investigate an existing object. This might be a component, method, or structure that helps a certain community. Reverse engineering will help engineers innovate and discover by evaluating currently available items on the market.

• Construct a new version of an old product: It is crucial to make an effort to know how a current product functions in order to revamp it. Engineers will be able to smoothly recreate outmoded items while preserving quality since reverse engineering provides the opportunity to work on outdated quirks in an earlier system. Reverse engineering can guarantee that there are no quality lapses.

• Identify product weaknesses: A product's flaws can be found through reverse engineering. This contributes to ensuring the consumers' security and well-being. Reverse engineering enables the discovery of all such issues during the research process itself, as opposed to learning about them following the distribution phase.

• Market items that are less priced and more effective: Reverse engineering's main objective is to guide engineers toward success and innovation. Reverse engineering is a tool that engineers may employ to cut the cost of production while maximizing a product's efficacy.

• Building a CAD model for future use: A fully functional CAD file is needed for reverse engineering operations and is often kept around for future usage. In order to digitally inspect engineering parts in case of future problems, a CAD file is often prepared. Both product expressiveness and engineering productivity have increased as a result of this reverse engineering approach.

• Motivate creative design: Last but not least, reverse engineering opens the door for creative design. Reverse engineering is a technique used in engineering to assist find systems that may be valuable for unrelated projects. Engineers may link projects with their prior knowledge and generate fresh ideas by using reverse engineering.

What are the Reverse Engineering Techniques?

Reverse engineering techniques are a collection of strategies used to comprehend and examine the design, structure, and operation of a product or system. This method entails the disassembly of the ultimate product or system in order to reveal its fundamental components, algorithms, and processes.

Reverse engineering techniques are crucial in the field of cybersecurity since they are used to find vulnerabilities and analyze malware. Security specialists use these methods to analyze harmful software, comprehend its actions, and create remedies to safeguard against cyber dangers. Through the process of reverse engineering malware, cybersecurity experts may discover concealed capabilities, detect possible avenues of attack, and formulate efficient approaches to minimize risks.

Reverse engineering methods techniques are as follows:

1. Disassembly: This method entails transforming machine code or binary files into assembly language that can be easily understood by humans. Disassembly enables engineers to comprehend the low-level instructions performed by a program and scrutinize its logic.

2. Decompilation: Decompilation refers to the transformation of compiled code into a computer language of higher abstraction. This method is very valuable when trying to comprehend the source code of a built software program.

3. Debugging: Debugging is scrutinizing the execution of a program inside a regulated setting in order to detect and rectify any problems. By systematically executing the code and closely observing the variables, developers may get valuable understanding of the program's functionality and detect any defects or weaknesses.

4. Code analysis: Code analysis approaches include scrutinizing the source code or binary files to detect trends, weaknesses, or possible optimizations. Analysis are performed either manually or by using specialized tools that automate the process.

What are the Best Reverse Engineering Tools?

Check out our list of tools used by some of the best software developers, organizations, and cybersecurity experts if you're seeking to reverse engineer software:

1. Ghidra: The National Security Agency (NSA) created the Ghidra reverse engineering tool, which was released to the public in 2019. It is one of the most sophisticated reverse engineering tools available right now. It's very well-liked for analyzing and unpacking malware.

   Ghidra's graphical user interface (GUI) is constructed using Java's Swing framework, a C++ decompiler, and Python extensions. Ghidra offers strong debugging tools for Windows and Linux and its reverse engineering capabilities.

2. IDA Pro: The most complete reverse engineering tool currently on the market, IDA Pro from Hex-Rays supports a variety of executable file formats and has a built-in command language. Although there is a free test edition with limited features, it is one of the priciest reverse engineering platforms.

   You may alter the presented data in real time, including functions, variables, names, and library functions, thanks to the IDA Pro disassembler's interactive nature. It's written in C++ and works with Linux, OS X, and Windows. The Hex-Rays decompiler is the most prominent of the plugins available for the IDA Pro platform. Software engineers decompress the native C++ processor code of many architecture types with this tool.

3. Hopper: Hopper is a disassembler for Linux and macOS. Both 32-bit and 64-bit executables are disassembled, decompiled, and debugged with this tool. The Linux version is constructed using Qt 5, whereas the Mac version is constructed using the Cocoa framework. Hopper has an SDK that lets you change its features and even add your own file and CPU support. The software's functionality is used using Python scripts, enabling binary transformation.

4. x64dbg: In order to analyze malware and do reverse engineering on executables for which you don't have the source code, you can use the free and open-source Windows binary debugger known as x64dbg. There are many features that are already accessible, and a strong plugin system allows you to add more.

5. PEiD: PEiD is an intuitive program that searches executable files for PE packers, cryptors, and compilers using its user-friendly interface. Since the software includes more than 600 distinct signatures in PE files, its detection rate is higher than that of other tools of a similar kind.

6. Hiew: The popular console hex editor for Windows is called Hiew (Hacker's view). This tool's capabilities include the capacity to read files in text, hex, and disassembly modes. For editing executable files, like COFF, PE, or ELF, Hiew is quite helpful. It features assemblers and disassemblers for x86 and x86-64 as well as ARM.

7. API Monitor: A software called API Monitor keeps track of every API function call made by programs and services. Additionally, both input and output data may be shown using this tool. Over 13,000 API function definitions and over 1,300 COM interface method definitions are pre-configured in API Monitor.

8. WinHex: WinHex is a hex editor for Windows with a wide variety of features and development tools. A typical text editor is unable to display checksums and the source code for software files, but WinHex can.

9. OllyDbg: OllyDbg is best suited for Microsoft Windows and functions as a 32-bit assembly-level analysis debugger. This reverse engineering tool focuses primarily on evaluating binary codes. When the source is unavailable, it is the most effective tool to utilize.

10. Apktool: Regarding Apktool, it's a third-party tool used for reverse engineering. It assists you in understanding the source material and decoding the resources. It would be great if you could recreate the full system using this help. You may then close the gaps in the system's defenses as a result of knowing where they are. This demonstrates how the appropriate tool assists you in eliminating threats and weaknesses.

11. Dex2jar: Dex2jar is essentially a lightweight API, to put it simply. You can completely grasp Dalvik Executable, which refers to the .dex or .odex format, with the aid of the appropriate tool. This tool mostly helps when working with .class files for Android and Java.

12. diStorm3: The diStorm is undoubtedly a top reverse engineering tool that is very well-liked by penetration testers. In 16, 32, and 64-bit modes, it is a relatively simple-to-use tool that aids in the process of disassembling the instructions. In actuality, it is the disassembler libraries' quickest. You may acquire source code that is highly legible, concise, and portable with the help of this program. You may use it in kernel modules and embedded modules, and it is entirely dependent on the C library.

13. Valgrind: For the purpose of profiling and debugging Linux programs, penetration testers utilize Valgrind. You can detect memory management issues and instantly recognize threading flaws by using the appropriate tool. This is accomplished by devoting several hours to stimulating bug-hunting until the program is stabilized. Additionally, it enables thorough profiling, which you can use to speed up the program's operations and eventually create many new tools.

14. MobSF: One of the most well-liked reverse engineering tools for all business sectors is Mobile Security Framework, or MobSF, which is used for malware investigation. It essentially functions as an automated reverse engineering tool with built-in mobile app pen-testing functionalities. This reverse engineering tool supports the malware analysis procedure. It has a security assessment methodology that makes it easier to carry out both static and dynamic analysis.

Figure 1. Best Reverse Engineering Tools

What is Reverse Engineering Protection?

Reverse engineering protection, commonly referred to as anti-reverse engineering, is a security mechanism designed to thwart unauthorized efforts to convert program binaries back into their original source code, therefore preserving the application from potential attacks. Anti-reverse engineering entails scrutinizing the source code to identify and thwart attempts to compromise the app's architecture, as well as to uncover security vulnerabilities such as the exposing of sensitive data like API URLs or private keys.

Software reverse engineering protectionis a crucial priority for developers, since it safeguards their intellectual property and prevents unwanted entry into their program.

What are Anti-Reverse Engineering Techniques?

By implementing a range of protective measures and adhering to industry best practices, reverse engineers will encounter more difficulty and spend more time attempting to reverse engineer your application. Some efficacious reverse enginering protection techniques are given below:

1. Code Obfuscation: Code obfuscation refers to the practice of intentionally making source code more difficult to understand or reverse engineer, often by using techniques such as renaming variables and functions, adding unnecessary code, and encrypting

   Code obfuscation is a method used to enhance the complexity of source code or binary code, hence making it more challenging to comprehend. The process includes altering the names of variables and functions to conceal their intended use, introducing superfluous code branches, and reorganizing code blocks. Although code obfuscation may not completely exclude dedicated reverse engineers, it may discourage casual efforts and considerably impede the process.

2. License Management: Develop and deploy resilient licensing management and software activation systems. This guarantees that only authorized users may use all the functionalities of your program. The implementation of license checks and online activation may pose significant challenges for reverse engineers attempting to develop functional cracks or key generators.

3. Anti-Debugging Techniques: Reverse engineers often use debuggers to scrutinize code execution and memory. Employ anti-debugging methodologies to identify instances when your code is being debugged and react appropriately. For instance, you have the ability to modify the behavior of your program or cause it to malfunction when it identifies the presence of a debugger.

4. Encryption: The process of converting information into a secret code or cipher to prevent unauthorized access.

   Utilize encryption techniques to safeguard critical sections of your code or data, therefore impeding the straightforward retrieval of information by anyone engaged in reverse engineering. Encryption keys should be securely kept and not included directly into the software's code. In this manner, even if those skilled in reverse engineering are able to extract encrypted data, the data will remain incomprehensible until the decryption key is available.

5. Hardware-Based Protection: Take into account hardware-based safeguards, such as Hardware Security Modules (HSMs) or dongles. These tangible devices have the ability to retain crucial components of your program, so presenting a formidable obstacle for reverse engineers attempting to get access to or alter them.

6. Legal Safeguards: Take into account legal safeguards such as End User License Agreements (EULAs) and copyright rights. These legal agreements may deter reverse engineering by clearly forbidding it and specifying probable legal ramifications.

7. Tamper Detection: Integrate tamper detection measures into your program. These techniques may verify the integrity of the executable file and detect any alterations or illegal modifications. If the program detects any tampering, it has the ability to either refuse to run or take the necessary action.

8. Dynamic Code Execution: Divide your code into several components and dynamically load them during runtime. This may impede reverse engineers' ability to comprehensively evaluate the whole program in a single attempt. In addition, using Just-In-Time (JIT) compilation or interpreting bytecode might obscure the logic of the code.

9. Threat modeling: Perform threat modeling activities to detect possible vulnerabilities and flaws in your program. To properly prioritize security measures, it is crucial to comprehend the most probable attack pathways.

10. Ongoing updates and patching: Regularly update your program to rectify flaws and counteract reverse engineering efforts. To safeguard the integrity of your software, it is crucial to adopt a proactive and responsive approach towards security concerns, which will effectively discourage reverse engineers.

Is Reverse Engineering Illegal?

Reverse engineering treads a delicate line in intellectual property law since it may be used to rebuild source code. Reverse engineering is generally expressly forbidden in software licensing agreements. Software businesses worry, and properly so, that reverse engineering may expose their proprietary algorithms and techniques in a more direct way than external machine observation. There isn't blanket legislation against reverse engineering, though.

It is unclear if reverse engineering is lawful because it is a necessary step in disabling copy protection systems. It is unlawful to patch software in order to get around copy protection or digital rights management systems. Software for reverse engineering is not. Reverse engineering might become unlawful under the new legislation, which would be a severe setback for the average software user (especially the common and curious user). An absolute ban on reverse engineering would be analogous to a ban on opening your car's hood to make repairs. Users of cars would be compelled by law to take their vehicles to the dealership for all repairs and maintenance under such a system.

Reverse engineering in open-source projects requires adherence to copyright regulations, and dividing the programmers into two teams is a frequent solution to this issue. Group 1 is responsible for writing the requirements and disassembling the firmware and program code. the second team that uses these criteria to create a program.

Fair use permits the copying of copyrighted content without the owner's consent in a few specific situations. The law often works in favor of the reverser when it comes to reverse engineering and fair usage. However, a "fair use" classification will nearly never be given to something that detracts from the original product's value. Also bear in mind that violating the conditions of the user license is not permitted under fair usage.

• Act on Digital Millennium Copyright: In order to make any service or equipment with the intention of weakening or deleting DRM (Digital Rights Management) copyright violation, the Digital Millennium Copyright Act was put into place in 1998. The statute outlaws the creation, marketing, or use of any product with the intention of evading any DRM. However, the DMCA has an exemption that allows the reverse engineering to be done for interoperability between software components.

• Agreement for End-User Licensing (EULA): An end-user licensing agreement (also known as a EULA) is a contract between the user and the software developer. It provides a set of restrictions on what the user may and may not do when using the product, outlining the conditions under which the user may use it. This agreement may specify the number of copies that may be created or the circumstances in which it may be reverse-engineered.

  An end-user licensing agreement (EULA) is often shown on a click-through screen when you buy or install the software. You must read and accept the software license, which is a legal document. You are frequently requested to click "I AGREE" in response to a EULA agreement shown on the website while downloading software online.

Why is Reverse Engineering Unethical?

Is reverse engineering unethical? This topic is hotly contested and does not appear to have a simple solution. Intellectual property is the main reason against reverse engineering. Is it OK for others to "disassemble" a product that a person or organization creates in order to figure out how it works inside? In Lexmark's opinion, no. Lexmark and similar businesses believe it is immoral for others to reverse engineer their goods since they invest time and money into product development. Additionally, products like Bit Keeper have suffered as a result of reverse engineering techniques. Why should businesses and individuals invest significant efforts in acquiring intellectual property that may be reverse-engineered by rivals for a much lower price?