Antoine He gave me the virus, I would like to know what is inside.
I know better than to use words like "never happen," or "impossible," but consider that what's inside are thousands or more likely millions of 1s and 0s. It's a very long way from those 1s and 0s to whatever source code was used to create the virus, and no really direct way to get there.
You won't be able to just feed that virus into an application that will spit out instructions telling you what the virus does. About the best outcome you could hope for would be to disassemble the virus into opcodes -- the operation codes (numbers) that a processor understands.
There won't be any variable names, just memory locations (numbers). Nor would there be any keywords from a symbolic, or high-level, computer language. Those 1s and 0s have no idea what computer language created them. And the compiler or assembler that reads the program code and turns it into an executable doesn't leave such keywords and variable names in its output. Just numbers.
So as I wrote, "impossible" might be a stretch, but unless you have an advanced degree in CS, the right software tools and experience, and lots and lots of spare time, you'll find it damn near impossible to understand what's in that virus by looking at it.
It can be more useful to execute the code in a debugger, step by step, and watch what it does, but without the symbols that were removed by the compiler (or assembler), you're still just watching opcodes do their thing. E.g., thousands of tiny tasks like "put this value in that register, and push it onto the stack, then jump to a memory location and execute the instructions you find there."
