Well done
Being the subject of an attack is one thing, being able to shrug it off and resume functioning without either having lost important data or paying the miscreants is, unfortunately, another thing entirely.
Well done to UKRI, who has apparently been some of the too rare institutions that had proper backup plans and procedures, and was capable of implementing them quickly.
Let's just hope that they've found the entry point, and will do what is required to plug the hole so that the miscreants have to find another way in.