Co-op Group have now admitted a significant amount of member (customer) information has been stolen by DragonForce Ransomware Cartel, saying they "accessed data relating to a significant number of our current and past members" - around 20 million people. The Membership database, basically. That includes home addresses and phone numbers etc.
Up until now Co-op hadn't even used the words cyber or threat actor, referring to an "IT issue" and "third party" in comms.