“...is that the admin user name and password was “admin”.”
That is REALLY hard to believe.
They probably used “password” for the password.
Actually, it was their Argentina site, and the pair was indeed admin/admin
https://www.cnet.com/news/equifax-argentina-vulnerability-admin/
Admin/admin is the second most common default out of the box login for IT equipment after admin/password. There are a *lot* of people too stupid to realize you’re supposed to change it.