Name:Linux Auditd Setuid Using Setcap Utility id:1474459a-302b-4255-8add-d82f96d14cd9 version:2 date:2024-09-30 author:Teoderick Contreras, Splunk status:production type:TTP Description:The following analytic detects the execution of the 'setcap' utility to enable the SUID bit on Linux systems. It leverages Linux Auditd data, focusing on process names and command-line arguments that indicate the use of 'setcap' with specific capabilities. This activity is significant because setting the SUID bit allows a user to temporarily gain root access, posing a substantial security risk. If confirmed malicious, an attacker could escalate privileges, execute arbitrary commands with elevated permissions, and potentially compromise the entire system. Data_source:
-Linux Auditd Execve
search:`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as dest | where LIKE (process_exec, "%setcap %") AND (LIKE (process_exec, "% cap_setuid+ep %") OR LIKE (process_exec, "% cap_setuid=ep %") OR LIKE (process_exec, "% cap_net_bind_service+p %") OR LIKE (process_exec, "% cap_net_raw+ep %") OR LIKE (process_exec, "% cap_dac_read_search+ep %")) | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec dest | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)`| `linux_auditd_setuid_using_setcap_utility_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://www.hackingarticles.in/linux-privilege-escalation-using-capabilities/ 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:90 impact:90 message:A [$process_exec$] event occurred on host - [$dest$] to set the SUID or SGID bit on files using the setcap utility. mitre_attack_id: - 'T1548.001' - 'T1548' observable: name:'dest' type:'Endpoint' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' - 'argc' - 'process_exec' risk_score:81 security_domain:endpoint
