O365 Admin Login to Uncommon Microsoft Cloud Apps

This rule detects successful login activity by administrative users to Microsoft Office 365 applications that are not part of a predefined list of common, first-party Microsoft cloud applications. This helps identify potentially unauthorized or unusual access to less common applications within the O365 ecosystem by privileged accounts. The rule specifically targets 'USER_LOGIN' events from 'Office 365' where the login is allowed and the application ID is not in the 'first_party_ms_cloud_apps' list. It also filters for users present in an 'msazure_admin_watchlist'.