Decompilation is the process of translating compiled software—such as an executable or library—into a higher-level representation that people can inspect. The result may resemble source code, but it usually does not restore the original names, comments, structure, or exact source. It can help analysts understand a program’s behavior when its source code is unavailable.
In cyber security, researchers and defenders use decompilation to examine suspicious programs, investigate vulnerabilities, and understand how software handles data or communicates. Attackers can also use it to study applications, locate weaknesses, or extract embedded secrets. In software reimplementation, decompiling code is distinct from observing a program’s inputs and outputs: it involves examining the compiled program itself. Decompilation may be subject to legal or contractual restrictions, so authorization and applicable rules matter.