CleanTalk – Check IP Addresses, Email, Subnet, Domain for Spam in Blacklists Database
https://cleantalk.org/blacklists

AbuseIPDB – hackers, spammers, and abusive activity
https://www.abuseipdb.com/

AlienVault – edit url
https://otx.alienvault.com/indicator/ip/1.1.1.1

IPQualityScore – Detect high risk IP addresses and check IP fraud scores
https://www.ipqualityscore.com/free-ip-lookup-proxy-vpn-test/lookup/

MXToolBox – RBL checks
https://mxtoolbox.com/blacklists.aspx

Log4J Scanners
https://raw.githubusercontent.com/CriticalPathSecurity/Public-Intelligence-Feeds/master/log4j.txt

SURBL
https://surbl.org/