It’s been common knowledge for years that local Windows Active Directory networks are vulnerable to NTLM relay and pass-the-hash attacks that can allow attackers to move laterally through networks and access additional machines and resources. Since some of these attacks exploit design decisions in the authentication protocols used inside Windows networks, they cannot be simply patched by Microsoft with changes in software. Organizations need to take defense-in-depth measures that involve stricter configurations and additional controls to protect themselves.
With the adoption of hybrid networks, where parts of the networks are local and parts are in the cloud, enterprises now rely on services such as Azure Active Directory (Azure AD) to allow its various machines to authenticate to each other. But Azure AD is quite different from local AD as it uses different protocols and has new features that expand the networking possibilities of organizations. However, according to presentations last month at the Black Hat USA security conference, it also offers new possibilities for attackers.