The Australian Cyber Security Centre has issued guidance on domain name system (DNS) security for domain resolvers and owners. The guidance for domain resolvers (trusted agents that query the DNS server hierarchy to match and provide an internet protocol address for a web browser to connect to) outlines mitigation strategies to help reduce the risks of DNS resolver subversion or compromise and to improve the security of DNS infrastructures. It looks at several types of attacks involving DNS resolvers, such as DNS spoofing, surveillance of DNS requests, misuse of encrypted DNS, and DNS as a malware covert channel. The guidance for domain owners offers mitigation strategies to reduce the risks of misuse of domain names and associated resources. It covers common types of attacks against domain names such as type-squatting, domain registration hijacking, and denial of service.