The "Cron Job Created or Modified" detection rule focuses on monitoring changes to Linux cron jobs, which are scheduled tasks that can run commands or scripts at predefined intervals. Attackers may exploit cron job configurations for persistence and command execution following an unauthorized gain of access. This rule is built to detect creation or renaming events of cron job files across several directories, including /etc/cron.* and /var/spool/cron/crontabs. The rule captures events with a focus on monitoring for malicious behavior in cron job management, providing a robust mechanism for threat detection against potential abuse by malicious actors. Additionally, investigation guidelines are offered to handle alerts effectively, including indicatives of potential malicious activity and the necessary steps for remediation.