Apility.io is a Minimal and Simple anti-abuse API blacklist lookup tool. It helps users to know immediately if an IP, Domain or Email is blacklisted. The ExoneraTor service maintains a database of IP addresses that have been part of the Tor network. The Free intelligence source for current and historical DNS information, WHOIS information, finding other websites associated with certain IPs, sub domain knowledge and technologies. There is a free threat intelligence parsed and aggregated by Critical Stack Intel.”]
Source: https://gbhackers.com/cyber-threat-intelligence-tools/