The rule 'Slack User Privileges Changed to User' is designed to monitor and respond to changes in user roles within the Slack environment, specifically when an account's role is downgraded from an elevated level (such as Admin or Owner) to a standard user. This is critical for maintaining security and compliance, as such changes could indicate either a necessary administrative action or potentially malicious activity aimed at limiting access to sensitive information. The rule incorporates logs from Slack Audit Logs with a medium severity rating, indicating that while this action may not be catastrophic, it still warrants attention. The rule utilizes two primary test cases: one to detect when a role change occurs from Admin to User and another to ensure that no unauthorized role changes from User to Admin take place simultaneously. Both tests assess the attributes of the log entry to confirm the outcome matches the expected results, thus providing a reliable means of detecting inappropriate or unauthorized privilege modifications.