[ThatPlayer]

> This isn't the equivalent of steeling original code but more like generating a brand new code that would compile to the same executable.

That doesn't make it not copyright infringement. As long as it's based on the same executable, that's a derivative work. In the same way if I were to recreate Star Wars A New Hope with new actors and new sets. If I were to play a cover of Micheal Jackson's Thriller with new instruments and new voices.

That's why clean-room design is a thing. To recreate the same function not based off the copyrighted executable, but rather its interactions with the user, other programs, and files. Interactions that aren't copyrightable.

[qwery]

You could do a clean-room implementation[0] of Michael Jackson's Thriller and the rights holders could still take you to court and have a good shot at winning. You could have never heard Thriller, come up with an obvious[1] melodic phrasing that some lawyers reckon sounds close enough and still get sued.

Of course, none of that makes it copyright infringement, only the (would-be) judge does.

[0] The product of which is roughly equivalent to a cover

[1] obvious to a musician or composer