Quad9 DNS Service
The Global Cyber Alliance (GCA) has partnered with IBM and Packet Clearing House to launch a free public Domain Name Service system. The system is intended to block domains associated with botnets, phishing attacks, and other malicious Internet hosts. The service is named Quad9 and it will not return name resolutions for sites that are identified via threat feeds the service aggregates daily. The DNS IPv4 number is 9.9.9.9.
https://www.globalcyberalliance.org/initiatives/quad9.html