Deleted Recovery from EX4100

We are running an EX4100 with 4x8TB HDDs. Recently we were hit by a virus which deleted all data in all shares (so much for having a NAS for backup storage!).
As there was no recycle bin configured (due to the files being very large backup files) it’s not possible to retrieve anything through the normal method.
My question is, is it possible to mount the disks using either a linux environment -or- run a tool such as R-Studio on Windows which can reconstruct an est3 RAID mirror in software and then scan the disk using relevant tools for deleted files? Or alternatively try to recovery via the NAS ssh?
(Very little if anything would have been written to the disks after the event so there’s a good chance the files are there and accessible with the right recovery method)
Would the partition or disks have any kind of encryption on? If yes, can this be still mounted in a recovery environment?

Google search: linux undelete ext4

If you have encrypted your volumes then extundelete will not work. Here you may have to send your hard drives to a specialist data recovery organisation.