I can't comment on the correct approach in that case, I'm under qualified. I would urge you to make sure you have good backups in a location that can't be compromised (as in, you won't wake up tomorrow to fine them all deleted). If your system already supports this, all the better. Keep in mind the worst case scenario here is that every production server is wiped, which is essentially close to the situation of a natural disaster at the site they are housed. If you don't have a plan on how to deal with a situation like this (disaster recovery/business continuity plans), such as redeploying to the cloud or to a different cloud, or a different datacenter, then that's a thought for the future (and the present if you have time).

I assume a professional computer security firm could help, but I don't know enough about the incentives at play to know whether that's good in practice (if they often deal with situations like this and not just hardening/forensics, I assume they would have good advice). I have no idea what that costs, and whether your business can afford it.