I’d be looking at the tools used by security researchers to analyse binary files. They seem the most appropriate I’d you really want a “general purpose” tool fo

I’d be looking at the tools used by security researchers to analyse binary files. They seem the most appropriate I’d you really want a “general purpose” tool for efficiently extracting chunks of structured data from arbitrary structured data files. Tools like the ones here https://awesomeopensource.com/projects/binary-analysis https://awesomeopensource.com/projects/binary-analysis such as radare2, or bap. But since these are normally used for dynamic research oriented workflows you may find the performance inadequate, and they will be more focused on extracting security relevant data. But the underlying libraries, the tool chains, and just generally the way these tools are built for smashing open arbitrarily packed and compressed executable data files will likely be at least a useful learning resource even if none of it is directly usable for solving your specific problem.