[MagicPropmaker]

And if it's protected as a "trade secret" and not a copyright (or patent) then you probably can use it without question.

[ufo]

Software is copyrighted "by default". You don't need to apply for copyright like you would need to do with a patent.

[MagicPropmaker]

https://www.uspto.gov/patents-getting-started/international-...

USPTO explanation of difference between a Patent, Copyright, and Trade Secret.

[detaro]

The software could contain a trade secret, and someone could discover it from reading the source (e.g. the banks magic evaluation function for credit ratings, or their trading strategy, or ...). That doesn't grant them any protected right on the software, which is protected by copyright.