What Is Deobfuscation?
It can also be used as an investigative technique to help find vulnerabilities in software. For example, a deobfuscator can help you understand what an attacker might have done to exploit your application.
deobfuscators are often used to unpack, clean, and rewrite source code, freeing up intermediate and late-stage compilation. Today, many developers use deobfuscators to investigate and reverse-engineer code, or to analyze the code of other developers.
When an application developer writes code, sometimes they don’t know where it will be used. A web checkout flow, for instance, could easily have different variables and expressions unique to the application. But the author could forget that some aspects may result in different checkout flows on different websites.
How Does Deobfuscation Work?
Obfuscation sometimes uses complex phrases and redundant logic to make the code difficult to read for programmers. The purpose is for them to be difficult to understand the true content of the message. This obfuscation of code, or stating something in several words and phrases to confuse, such as repeating a complex story in similar ways is intentional. It is a technique that is used so a programmer won’t have to
Many developers simply copy their source code into the deobfuscator and let it do the work. This way, they don’t have to worry about whether they’ve missed any security issues while they review the code manually. However, this method can be time-consuming and tedious, which is why most developers rely on a deobfuscator to make their job easier.
What Are the Benefits of Deobfuscation?
A deobfuscator is an important tool for software developers. It takes obfuscated code, breaks the code down into its components, and then makes it easy to understand again. This way, you can figure out exactly what your code is doing and how it’s performing.
Additionally, a deobfuscator helps you keep your applications secure by finding security vulnerabilities that you may have missed while developing your application. Security vulnerabilities like XSS (cross-site scripting) and SQL injection are often overlooked during development because they’re difficult to detect without a deobfuscator's help.
With a deobfuscator, you can also easily reverse-engineer the code of other developers. That’s because the developer won’t be able to use any obfuscation tricks or shortcuts to hide their work from you. They'll be forced to write clear and readable code that can be easily understood by anyone who’s looking at it.
The first step in deobfuscation is to identify the type of obfuscation used and create the appropriate preprocessors and post-processors. The next step is to run a series of deobfuscation methods in a loop until they are no longer effective. Once that happens, it's time to apply post-processors to the now deobfuscated code.
Finally, the code is normalized (e.g., turning bracket[‘notation’] into a dot. notation) to remove any dead code. When dealing with code, it is important to know whether a method is using eval to resolve its output or not. Using eval is considered unsafe even when running it in a sandbox environment like vm2.