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Linux Add Files In Known Crontab Directories

The following analytic detects unauthorized file creation in known crontab directories on Unix-based systems. It leverages filesystem data to identify new files in directories such as /etc/cron* and…

Description

The following analytic detects unauthorized file creation in known crontab directories on Unix-based systems. It leverages filesystem data to identify new files in directories such as /etc/cron* and /var/spool/cron/*. This activity is significant as it may indicate an attempt by threat actors or malware to establish persistence on a compromised host. If confirmed malicious, this could allow attackers to execute arbitrary code at scheduled intervals, potentially leading to further system compromise and unauthorized access to sensitive information.

Detection logic

Detection requirements

Platform
ESXiLinuxmacOS

The rule states no platform. This is derived from the ATT&CK technique it maps to.

Log source category
sysmon_for_linux_eventid_11

Known benign triggers

  • Administrator or network operator can create file in crontab folders for automation purposes. Please update the filter macros to remove false positives.

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