The 'Auditd Max Login Sessions' detection rule is designed to identify scenarios where a user has reached the maximum number of allowed login sessions permitted by security policies in a Linux environment. This condition is indicative of potential abuse, where attackers may utilize valid accounts to create unauthorized access to resources. The rule works by querying the 'auditd' logs within the index specified ('auditbeat-*') and looks for specific actions that denote an exceeded session limit, specified in the query as 'opened-too-many-sessions-to'. These monitoring efforts not only help in identifying attempted unauthorized access through valid accounts but also play a crucial role in enforcing the best practices of session management and integrity of access controls. This rule has a medium-risk score of 47, reflecting its importance in initial access and persistence tactics detailed in the MITRE ATT&CK framework, specifically under Valid Accounts. The rule has been deprecated since July 25, 2022, indicating that while it served an important purpose, updates or replacements may now be available.