Name:Linux Auditd Sudo Or Su Execution id:817a5c89-5b92-4818-a22d-aa35e1361afe version:2 date:2024-09-30 author:Teoderick Contreras, Splunk status:production type:Anomaly Description:The following analytic detects the execution of the "sudo" or "su" command on a Linux operating system. It leverages data from Linux Auditd, focusing on process names and parent process names. This activity is significant because "sudo" and "su" commands are commonly used by adversaries to elevate privileges, potentially leading to unauthorized access or control over the system. If confirmed malicious, this activity could allow attackers to execute commands with root privileges, leading to severe security breaches, data exfiltration, or further system compromise. Data_source:
-Linux Auditd Proctitle
search:`linux_auditd` `linux_auditd_normalized_proctitle_process` | rename host as dest | where LIKE(process_exec, "%sudo %") OR LIKE(process_exec, "%su %") | stats count min(_time) as firstTime max(_time) as lastTime by process_exec proctitle normalized_proctitle_delimiter dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`| `linux_auditd_sudo_or_su_execution_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 execute this command. Please update the filter macros to remove false positives. References: -https://attack.mitre.org/techniques/T1548/003/ 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: - 'Linux Privilege Escalation' - 'Linux Persistence Techniques' - 'Compromised Linux Host' asset_type:Endpoint confidence:50 impact:50 message:A [$process_exec$] event occurred on host - [$dest$] to execute the sudo or su command. mitre_attack_id: - 'T1548.003' - 'T1548' observable: name:'dest' type:'Endpoint' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'proctitle' risk_score:25 security_domain:endpoint
