Active Directory (AD)

Active Directory (AD) is Microsoft's directory service for Windows environments. It centrally manages an organization's users, groups, computers and policies and has been the backbone of login and permission assignment in many organizations for decades.

AD is structured in domains and organizational units; group policies enforce configurations across the board, and authentication takes place via protocols such as Kerberos. In the cloud, Microsoft Entra ID (formerly Azure AD) complements the classic directory service – both coexist in most environments. On the security side, AD is at the same time the most attractive target of attack in the corporate network: whoever gains control over the directory effectively controls all identities. Hardening, permission hygiene and the monitoring of privileged accounts are therefore among the most important basic measures.

During modernization, AD rarely remains alone: via Directory Integration, existing directories are connected to modern identity platforms – the protection of the directory service itself is a core topic of Identity Security.