Name:Linux Auditd Stop Services id:43bc9281-753b-4743-b4b7-60af84f085f3 version:2 date:2024-09-30 author:Teoderick Contreras, Splunk status:production type:TTP Description:The following analytic detects attempts to stop or clear a service on Linux systems. It leverages data from Linux Auditd, focusing on processes like "systemctl," "service," and "svcadm" executing stop commands. This activity is significant as adversaries often 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. Data_source:
-Linux Auditd Service Stop
search:`linux_auditd` type=SERVICE_STOP | rename host as dest | stats count min(_time) as firstTime max(_time) as lastTime by type pid UID comm exe dest | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)`| `linux_auditd_stop_services_filter`
how_to_implement:To implement this detection, the process begins by ingesting auditd data, that consist 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. References: -https://www.welivesecurity.com/2022/04/12/industroyer2-industroyer-reloaded/ -https://cert.gov.ua/article/39518 drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'Industroyer2' - 'Data Destruction' - 'AwfulShred' - 'Compromised Linux Host' asset_type:Endpoint confidence:70 impact:70 message:A service event - [$type$] event occured on host - [$dest$] to stop or disable a service. mitre_attack_id: - 'T1489' observable: name:'dest' type:'Endpoint' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'type' - 'pid' - 'UID' - 'comm' - 'exe' risk_score:49 security_domain:endpoint
