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pyth0n1c
80 lines
4.0 KiB
YAML
80 lines
4.0 KiB
YAML
name: Linux Auditd Setuid Using Setcap Utility
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id: 1474459a-302b-4255-8add-d82f96d14cd9
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version: 4
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date: '2025-02-10'
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author: Teoderick Contreras, Splunk
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status: production
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type: TTP
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description: The following analytic detects the execution of the 'setcap' utility
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to enable the SUID bit on Linux systems. It leverages Linux Auditd data, focusing
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on process names and command-line arguments that indicate the use of 'setcap' with
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specific capabilities. This activity is significant because setting the SUID bit
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allows a user to temporarily gain root access, posing a substantial security risk.
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If confirmed malicious, an attacker could escalate privileges, execute arbitrary
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commands with elevated permissions, and potentially compromise the entire system.
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data_source:
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- Linux Auditd Execve
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search: '`linux_auditd` `linux_auditd_normalized_execve_process` | rename host as
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dest | rename comm as process_name | rename exe as process | where LIKE (process_exec,
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"%setcap %") AND (LIKE (process_exec, "% cap_setuid+ep %") OR LIKE (process_exec,
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"% cap_setuid=ep %") OR LIKE (process_exec, "% cap_net_bind_service+p %") OR LIKE
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(process_exec, "% cap_net_raw+ep %") OR LIKE (process_exec, "% cap_dac_read_search+ep
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%")) | stats count min(_time) as firstTime max(_time) as lastTime by argc process_exec
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dest | `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)`|
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`linux_auditd_setuid_using_setcap_utility_filter`'
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how_to_implement: To implement this detection, the process begins by ingesting auditd
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data, that consists of SYSCALL, TYPE, EXECVE and PROCTITLE events, which captures
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command-line executions and process details on Unix/Linux systems. These logs should
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be ingested and processed using Splunk Add-on for Unix and Linux (https://splunkbase.splunk.com/app/833),
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which is essential for correctly parsing and categorizing the data. The next step
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involves normalizing the field names to match the field names set by the Splunk
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Common Information Model (CIM) to ensure consistency across different data sources
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and enhance the efficiency of data modeling. This approach enables effective monitoring
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and detection of linux endpoints where auditd is deployed
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known_false_positives: Administrator or network operator can execute this command.
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Please update the filter macros to remove false positives.
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references:
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- https://www.hackingarticles.in/linux-privilege-escalation-using-capabilities/
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drilldown_searches:
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- name: View the detection results for - "$dest$"
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search: '%original_detection_search% | search dest = "$dest$"'
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earliest_offset: $info_min_time$
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latest_offset: $info_max_time$
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- name: View risk events for the last 7 days for - "$dest$"
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search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$")
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starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime
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values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories)
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as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic)
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as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)`
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| `security_content_ctime(lastTime)`'
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earliest_offset: $info_min_time$
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latest_offset: $info_max_time$
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rba:
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message: A [$process_exec$] event occurred on host - [$dest$] to set the SUID or
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SGID bit on files using the setcap utility.
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risk_objects:
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- field: dest
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type: system
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score: 81
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threat_objects: []
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tags:
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analytic_story:
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- Linux Privilege Escalation
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- Linux Persistence Techniques
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- Compromised Linux Host
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asset_type: Endpoint
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mitre_attack_id:
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- T1548.001
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product:
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- Splunk Enterprise
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- Splunk Enterprise Security
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- Splunk Cloud
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security_domain: endpoint
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tests:
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- name: True Positive Test
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attack_data:
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- data:
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https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1548.001/linux_auditd_setuid/linux_auditd_setcap_priv.log
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source: /var/log/audit/audit.log
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sourcetype: linux:audit
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