A brief update on our Mailman attack. After analyzing the attack pattern, I've added a new long-term measure into Mailman that is preventing these botnet subscription attempts from being honored (whilst still allowing humans to subscribe). I then turned my attention to Cloudflare. After some experimentation (and manual-reading!) I discovered that - with a little custom crafting - one can actually use Cloudflare to mitigate this type of attack quite nicely. I inserted some custom rules that have all but halted the incoming flood completely. So Mailman subscription service is back online (for humans only!) and we appear to be back to normal. Thank you for your patience during this interruption. Glen -- Glen Barney IT Director AMS (IETF Secretariat)
