Which tool might a threat actor use to examine the source code of a program they detected during a scan?

The decompiler is a tool that converts executable programs back into a higher-level programming language code, allowing a threat actor to examine the source code or the logic of the program. This process is crucial for understanding how the program operates, identifying vulnerabilities, analyzing functionality, and possibly manipulating the program for malicious purposes.

By using a decompiler, a threat actor gains insights into the original structure and data flow of the software, which can help identify exploits or weaknesses that could be exploited. The ease of understanding the program's logic, control structures, and algorithms is what makes decompilation particularly valuable in a security context.

Other tools mentioned, such as debuggers and disassemblers, serve different functions. A debugger is used for examining and testing code execution line-by-line, with the primary goal of identifying and fixing errors rather than fully retrieving high-level source code. A disassembler translates binary code into assembly language, which is low-level and may be difficult for someone looking to understand the program's original source code. A sniffer is a network monitoring tool, used to capture and analyze data packets traveling over a network, and does not pertain to analyzing the code of a single program.