When they say "The episode occurred when threat actors gained access to this third party legacy system which was not decommissioned properly. " for me it sounds

When they say "The episode occurred when threat actors gained access to this third party legacy system which was not decommissioned properly. " for me it sounds like a not properly wiped disk that got into the the bad guys hands. It would be interesting to know more to be prepared for proper decommissioning of hardware.