We have no information about him.
Already using Cloudflare, it did seem to detect some of his BotNet(~3500 instances) but not enough to stop the load he put on us. (edited)
Cloudflare Rate Limiting is just too expensive and "I'm under attack" mode just breaks the site in places anyway.
I've reached out to Cloudflare support to try identify his BotNet from the times when he took it down.
Any help would be much appreciated.
From that page: "you should contact law enforcement if your organization received a threat prior to the attack, or received a demand for money in return for not being attacked"
We setup copies of the site so we could quickly rotate it to new IPs during the attack and signed up for the CloudFlare business plan for a month or two during the attacks every year.
This kept the site up for us. We also posted a message on the home page so our users would know what was going on.
We were able to use under attack mode without it affecting the site too much.
Good luck riding it out.
Windows or Linux systems?
You can do some mitigation with iptables in linux.
>He has proved that he can by taking our sites offline for a minute.
What did this person take down exactly? The web server, or did he reboot the system?
Three different people from Cloudflare reached out to resolve the problem. They are awesome!