This was reported first at the begining of May. They got into the server via that Salt vuln and just ran crypto miners on the server, they didn't (as far as anyone knows) use the keys to do anything bad. From the original email reporting the problem: (the attacker doesn't seem to realize that they gained access to the keys and were running other services on the instracture)
If you do not assume that everything bad that could have happened, did happen, then you will have some interesting explaining to do later, with lawyers.