This rule is designed to detect the addition of a new file or path exclusion in MacOS Time Machine by monitoring the execution of the "tmutil" utility. The detection mechanism works by observing process creation events that involve the "tmutil" executable paired with command line arguments indicating a request to add exclusions, specifically looking for the "addexclusion" command. The concern here is that malicious actors may utilize this command to prevent specific files from being backed up in Time Machine, thus avoiding their detection during forensic investigations. The rule will trigger upon the identification of processes that match the defined criteria, providing a medium level alert. Administrators should be aware that legitimate administrative functions may cause false positives, which is noted in the rule documentation, and careful analysis of such alerts will be necessary to distinguish between true threats and normal operations.