Linux Deletion Of Init Daemon Script
Description
The following analytic detects the deletion of init daemon scripts on a Linux machine. It leverages filesystem event logs to identify when files within the /etc/init.d/ directory are deleted. This activity is significant because init daemon scripts control the start and stop of critical services, and their deletion can indicate an attempt to impair security features or evade defenses. If confirmed malicious, this behavior could allow an attacker to disrupt essential services, execute destructive payloads, or persist undetected in the environment.
Query · spl
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Filesystem
WHERE Filesystem.action=deleted Filesystem.file_path IN ( "/etc/init.d/*")
BY Filesystem.action Filesystem.dest Filesystem.file_access_time
Filesystem.file_create_time Filesystem.file_hash Filesystem.file_modify_time
Filesystem.file_name Filesystem.file_path Filesystem.file_acl
Filesystem.file_size Filesystem.process_guid Filesystem.process_id
Filesystem.user Filesystem.vendor_product
| `drop_dm_object_name(Filesystem)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `linux_deletion_of_init_daemon_script_filter`
Implementation guide
To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you can use the Add-on for Linux Sysmon from Splunkbase.
Known false positives
- Administrator or network operator can execute this command. Please update the filter macros to remove false positives.
Analyst notes
Known false positives: Administrator or network operator can execute this command. Please update the filter macros to remove false positives.