Several organizations maintain and publish free blocklists of IP addresses and URLs of systems and networks suspected in malicious activities on-line. Some of these lists have usage restrictions: Artists Against 419: Lists fraudulent websites ATLAS from Arbor Networks: Registration required by contacting Arbor Blackweb Project: Optimized for Squid CLEAN-MX Realtime Database: XML output available CriticalStack Intel … Continue reading Free Blocklists of Suspected Malicious IPs and URLs