I created some iptables rules, basically allowing incoming traffic from TCP/UDP Ports 80,53(for the bind server), 22, and blocking everything else incoming however I forgot to allow the ICMP protocol through the filter.
This resulted in expected issues with ping, traceroute, and everything else relying on ICMP. I also noticed a very peculiar thing happening. Our blog spam on the sites hosted almost quadrupled.
What could cause this? I wanted to figure out the issue before turning back on the firewall with ICMP enabled in case there's another explanation.