Mandiant Details Detection of Microsoft 365 and Azure AD Backdoors

Mandiant published guidance on detecting backdoors in Microsoft 365 and Azure Active Directory, highlighting how attackers can establish persistent access in cloud identity environments after initial compromise. The report focuses on abuse of identity and administrative features that let intruders maintain control over tenant resources, evade remediation, and regain access even after passwords are reset.

The guidance emphasizes hunting for persistence mechanisms tied to cloud accounts, applications, and federation settings in Microsoft environments, reflecting growing concern over identity-layer attacks against enterprise tenants. For defenders, the publication frames Microsoft 365 and Azure AD as critical investigation points during incident response because compromised identity infrastructure can provide long-term access across email, collaboration, and cloud administration services.