O365 Excessive SSO logon errors — Detection Rule
The following analytic detects accounts experiencing a high number of Single Sign-On (SSO) logon errors. It leverages data from the `o365_management_activity` dataset, focusing on failed user login attempts with SSO errors. This activity is significant as it may indicate brute-force attempts or the hijacking/reuse of SSO tokens. If confirmed malicious, attackers could potentially gain unauthorized access to user accounts, leading to data breaches, privilege escalation, or further lateral movement within the organization.