Azure AD External User Invitation from Common Public Domains
This rule detects when an external user is invited to Azure Active Directory (AAD) from a common, publicly available email domain (e.g., gmail.com, outlook.com, yahoo.com). This can be an indicator of an attacker attempting to establish persistence or gain initial access by inviting an external account they control, or it could be a legitimate business process for collaboration with external parties using personal email addresses.
Microsoft Sentinel (KQL)

