First time I've been hacked

So I have this Network drive (NAS). western digital (WD) MyBook live I’ve had it for probably 10 years now. I used to have it for photography files and business stuff but I don’t keep hard drives after 3 years so it’s been on a shelf mostly. it had backed up CDs and DVD movies on it and we had and used it as a media server. But streaming has provided us a better experience since we have a much better internet connection here than we had in Ontario. So it hadn’t been used and was put away again. A month ago my wife wanted to use it again, I guess it’s easier to pick something familiar from a list of stuff that was already selected by you so I set it up again for her. I’m not sure if she used it or not, I think she did… anyway I changed out some hardware on the network here and didn’t connect it back up and a couple of days ago she complained that she couldn’t connect to it and I reset everything and was greeted by a completely empty drive that I no longer had a password for, so I fixed the password issue and put it aside until I had some time and I just now discovered that all of these WD drives that were connected to the internet on June 23 were sent a factory reset command. all the files are gone … I guess there has been some reported luck recovering a few files but no file tables or file names for most of the files. Turns out it was some suspected Russian hacker group that might have compromised the security on these things years ago and they picked that day to pack up shop and delete the evendence