A hosted domain is a website or subdomain that runs on a provider-managed platform, such as a shared web host, content management service, or cloud publishing system. The owner may control content and settings, but the underlying infrastructure, DNS, certificates, and account access are partly handled by the provider.
This matters in cyber security because attackers often abuse hosted domains for phishing, malware delivery, command-and-control, or extortion pages. Defenders may also see legitimate hosted domains named in victim listings or threat claims, which can create confusion before verification. When investigating, teams should check platform accounts, publishing permissions, DNS records, and recent content changes to determine whether the domain was compromised, misused, or simply mentioned without proof.