Subscribing to the DShield Top 20 on a Palo Alto Networks Firewall
This link by Richard Porter provides a quick link to ip’s you can easily blacklist with any iptables or netfilter firewall. Ultimately, it provides a quick list of Tor nodes, known spammers and compromised hosts that any NOC/SOC would be interested in blocking. https://isc.sans.edu/diary/Subscribing+to+the+DShield+Top+20+on+a+Palo+Alto+Networks+Firewall/19365