The 'Crowdstrike Allowlist Removed' rule is designed to detect the deletion of an allowlist within the Crowdstrike platform. This detection is critical because the removal of allowlists can lead to increased security risks, as these lists are used to permit certain activities and configurations deemed safe. The rule utilizes event streams from Crowdstrike's security controls, capturing relevant events when an allowlist is deleted by a user. The rule defines multiple tests that cover scenarios such as successfully deleting both enabled and disabled allowlists, and capturing updates where allowlists are marked as inactive. An alert is triggered if an unexpected deletion or modification occurs, helping ensure that administrators are aware of any significant changes to the security configurations. Furthermore, the rule maps to the MITRE ATT&CK framework under tactic TA0040, which denotes 'Impact' and can help in behavioral analysis for user actions related to security settings.