"These messages included a phishing link that led to fake banking websites, which were used to harvest credentials."
Let's not forget the banks' culpability in this. They train their customers to be phished by sending emails, mostly marketing emails, with links in them. Two things should be made compulsory for banks:
1. No email sent to a customer should contain a link except for a few well-defined circumstances such as a password reset and certainly not without some previous interaction that ensures the customer is expecting it.*
2. Hammer home to the customers that any email purporting to be from the bank is fake, should be reported and the link should on no account be followed.
It probably wouldn't even be necessary for legislation to compel this. A regulatory requirement might be sufficient although legislation to make it a criminal offence to sign off sending such emails would be a good way to ensure the first requirement was obeyed.
* Ideally this should be eliminated by doing it off-net in a branch. Yes, real bank branches.