We weren't able to pin down who did it. They were good. My best guess is they are overseas, not in the US. There is a known weakness in this software we use. And worse yet a way to fairly easily find sites using it. I will not elaborate here. We were aware of them but are kinda tied to the software. We did do what we could to reduce the chances of being hit but couldn't eliminate them altogether.
This person was a much better and more knowledgeable hacker than any who have hit us before. But they really weren't all that mean. With the access they had if they had wanted they could have totally wiped out the site. They didn't. Just did a minimal amount of damage to show they could if they wanted to and moved on. I think the same person or group of persons hit thousands of sites in a period of a week or so world wide.