Is change of backup encryption key logged by Proxmox?

[aldomoro]

Hi

I heard about an attack, when hackers changed backup encryption key, waited several weeks and then they encrypted production VMs and IT team could not recovery anything, because their master key was not valid anymore.

Is change of backup encryption key logged by Proxmox?
How can I find where my key is stored in system, when I used "autogeneration key"?

Thank you