A DNS hijack is the unauthorized alteration of Domain Name System settings or records. DNS translates domain names into network destinations, so changing its configuration can send users to the wrong server or prevent them from reaching a service.
In cyber attacks, an intruder may change DNS through compromised registrar credentials, hosting accounts, or other control over DNS management. The result can be website redirection, service disruption, or misleading destinations, even without evidence that the application or its data was accessed. Defenders should secure registrar accounts with strong authentication, limit administrative access, monitor DNS changes, and verify records during incident response.