Linux Auditd Stop Services
Description
The following analytic detects attempts to stop a service on Linux systems. It leverages data from Linux Auditd. This activity is significant as adversaries often stop or terminate security or critical services to disable defenses or disrupt operations, as seen in malware like Industroyer2. If confirmed malicious, this could lead to the disabling of security mechanisms, allowing attackers to persist, escalate privileges, or deploy destructive payloads, severely impacting system integrity and availability.
Query · spl
`linux_auditd` type=SERVICE_STOP
| rename host as dest
| stats count min(_time) as firstTime max(_time) as lastTime
BY type pid comm
exe dest
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `linux_auditd_stop_services_filter`
Implementation guide
To implement this detection, the process begins by ingesting auditd data, that consists of SYSCALL, TYPE, EXECVE and PROCTITLE events, which captures command-line executions and process details on Unix/Linux systems. These logs should be ingested and processed using Splunk Add-on for Unix and Linux (https://splunkbase.splunk.com/app/833), which is essential for correctly parsing and categorizing the data. The next step involves normalizing the field names to match the field names set by the Splunk Common Information Model (CIM) to ensure consistency across different data sources and enhance the efficiency of data modeling. This approach enables effective monitoring and detection of linux endpoints where auditd is deployed
Known false positives
- Administrator or network operator can use this application for automation purposes. Please update the filter macros to remove false positives.
Analyst notes
Known false positives: Administrator or network operator can use this application for automation purposes. Please update the filter macros to remove false positives.