The people behind this kind of thing need to be set on fire, it's just evil behavior, whether or not they actually have the details they purport to have. I'm going to venture a guess that this, indeed, isn't a hack of Apple itself, and do simply have some password-reuse email/password combinations from other sites.
Time to turn on 2FA, if you haven't already, and never use the same password in more than one place - get a good password manager (I like 1Password) and use it to keep long random passwords that are separate for every site.