What is the ruling on downloading foreign medical books and references available online, in violation of intellectual property rights, and what is the meaning of the word "Harbi" in the context of its permissibility?

Copyrights are legally protected for their owners, whether they are Muslims or non-hostile disbelievers. It is not permissible to violate them. A hostile disbeliever is one with whom there is no covenant, no guarantee of safety, and no dhimmi contract between him and the Muslims.