TR-3997 - New Content - auditpol and audit policy tampering analytics

detections/endpoint/suspicious_event_log_service_behavior.yml → detections/deprecated/suspicious_event_log_service_behavior.yml

@@ -3,9 +3,9 @@ id: 2b85aa3d-f5f6-4c2e-a081-a09f6e1c2e40
 version: 6
 date: '2025-02-10'
 author: Mauricio Velazco, Splunk
-status: production
+status: deprecated
 type: Hunting
-description: The following analytic detects the shutdown of the Windows Event Log
+description: This search has been deprecated in favour of Windows Event Logging Service Has Shutdown . The following analytic detects the shutdown of the Windows Event Log
   service using Windows Event ID 1100. This event is logged every time the service
   stops, including during normal system shutdowns. Monitoring this activity is crucial
   as it can indicate attempts to cover tracks or disable logging. If confirmed malicious,

detections/endpoint/windows_ad_domain_controller_audit_policy_disabled.yml

@@ -1,7 +1,7 @@
 name: Windows AD Domain Controller Audit Policy Disabled
 id: fc3ccef1-60a4-4239-bd66-b279511b4d14
-version: 4
-date: '2024-11-13'
+version: 5
+date: '2025-01-28'
 author: Dean Luxton
 type: TTP
 status: production
@@ -53,7 +53,7 @@ rba:
   threat_objects: []
 tags:
   analytic_story:
-  - Sneaky Active Directory Persistence Tricks
+  - Windows Audit Policy Tampering
   asset_type: Endpoint
   mitre_attack_id:
   - T1562.001

detections/endpoint/windows_audit_policy_auditing_option_disabled_via_auditpol.yml

@@ -0,0 +1,62 @@
+name: Windows Audit Policy Auditing Option Disabled via Auditpol
+id: 663a7a50-b752-4c84-975b-8325ca3f6f9e
+version: 1
+date: '2025-01-27'
+author: Nasreddine Bencherchali, Splunk
+status: production
+type: TTP
+description: The following analytic identifies the execution of `auditpol.exe` with the "/set", "/option" and "/value:disable" command-line arguments used to disable specific auditing options of the audit policy. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity can be significant as it indicates potential defense evasion by adversaries or Red Teams, aiming to limit data that can be leveraged for detections and audits. If confirmed malicious, this behavior could allow attackers to bypass defenses, and plan further attacks, potentially leading to full machine compromise or lateral movement.
+data_source:
+- Sysmon EventID 1
+- Windows Event Log Security 4688
+- CrowdStrike ProcessRollup2
+search: '| tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_auditpol` Processes.process="*/set*" Processes.process="*/option:*" Processes.process="*/value:disable*" Processes.process IN ("*FullPrivilegeAuditing*", "*AuditBaseObjects*", "*AuditBaseDirectories*") by Processes.dest Processes.user Processes.parent_process Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_audit_policy_auditing_option_disabled_via_auditpol_filter`'
+how_to_implement: The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process name, and process original file name. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
+known_false_positives: None identified. Attempts to disable logging should be identified and understood.
+references:
+- https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-gpac/262a2bed-93d4-4c04-abec-cf06e9ec72fd
+- https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/auditpol-set
+drilldown_searches:
+- name: View the detection results for - "$user$" and "$dest$"
+  search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
+  earliest_offset: $info_min_time$
+  latest_offset: $info_max_time$
+- name: View risk events for the last 7 days for - "$user$" and "$dest$"
+  search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$",
+    "$dest$") 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: $info_max_time$
+rba:
+  message: An instance of $parent_process_name$ spawning $process_name$ was identified attempting to disable an audit policy auditing option on endpoint $dest$ by user $user$.
+  risk_objects:
+  - field: user
+    type: user
+    score: 60
+  - field: dest
+    type: system
+    score: 60
+  threat_objects:
+  - field: process_name
+    type: process_name
+tags:
+  analytic_story:
+  - Windows Audit Policy Tampering
+  asset_type: Endpoint
+  mitre_attack_id:
+  - T1562.002
+  product:
+  - Splunk Enterprise
+  - Splunk Enterprise Security
+  - Splunk Cloud
+  security_domain: endpoint
+tests:
+- name: True Positive Test - Sysmon
+  attack_data:
+  - data: 
+      https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.002/auditpol_tampering/auditpol_tampering_sysmon.log
+    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
+    sourcetype: XmlWinEventLog

detections/endpoint/windows_audit_policy_auditing_option_modified___registry.yml

@@ -0,0 +1,58 @@
+name: Windows Audit Policy Auditing Option Modified - Registry
+id: 27914692-9c62-44ea-9129-ceb429b61bd0
+version: 1
+date: '2025-01-27'
+author: Nasreddine Bencherchali, Splunk
+status: production
+type: Anomaly
+description: The following analytic detects potentially suspicious modifications to the Audit Policy auditing options registry values. It leverages data from the Endpoint.Registry data model, focusing on changes to one of the following auditing option values "CrashOnAuditFail", "FullPrivilegeAuditing", "AuditBaseObjects" and "AuditBaseDirectories" within the "HKLM\\System\\CurrentControlSet\\Control\\Lsa\\" registry key. This activity is significant as it could be a sign of a threat actor trying to tamper with the audit policy configuration, and disabling SACLs configuration. If confirmed malicious, this behavior could allow attackers to bypass defenses, and plan further attacks, potentially leading to full machine compromise or lateral movement.
+data_source:
+- Sysmon EventID 13
+search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry WHERE Registry.registry_key_name="*\\Control\\Lsa" Registry.registry_value_name IN ("CrashOnAuditFail", "FullPrivilegeAuditing", "AuditBaseObjects", "AuditBaseDirectories") BY Registry.registry_path Registry.registry_key_name Registry.registry_value_name Registry.registry_value_data Registry.process_guid Registry.dest Registry.user | `drop_dm_object_name(Registry)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_audit_policy_auditing_option_modified___registry_filter`'
+how_to_implement: To successfully implement this search, you need to be ingesting logs with the registry value name, registry path, and registry value data from your endpoints. If you are using Sysmon, you must have at least version 2.0 of the official Sysmon TA. https://splunkbase.splunk.com/app/5709
+known_false_positives: Active setup installer may add or modify this registry.
+references:
+- https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-gpac/262a2bed-93d4-4c04-abec-cf06e9ec72fd
+- https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/auditpol-set
+drilldown_searches:
+- name: View the detection results for - "$dest$" and "$user$"
+  search: '%original_detection_search% | search  dest = "$dest$" user = "$user$"'
+  earliest_offset: $info_min_time$
+  latest_offset: $info_max_time$
+- name: View risk events for the last 7 days for - "$dest$" and "$user$"
+  search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$",
+    "$user$") 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: $info_max_time$
+rba:
+  message: The auditing option $registry_value_name$ from the configured Audit Policy was modified on $dest$.
+  risk_objects:
+  - field: dest
+    type: system
+    score: 64
+  - field: user
+    type: user
+    score: 64
+  threat_objects: []
+tags:
+  analytic_story:
+  - Windows Audit Policy Tampering
+  asset_type: Endpoint
+  mitre_attack_id:
+  - T1547.014
+  product:
+  - Splunk Enterprise
+  - Splunk Enterprise Security
+  - Splunk Cloud
+  security_domain: endpoint
+tests:
+- name: True Positive Test - Sysmon
+  attack_data:
+  - data: 
+      https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.002/auditpol_tampering/auditpol_tampering_sysmon.log
+    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
+    sourcetype: XmlWinEventLog

detections/endpoint/windows_audit_policy_cleared_via_auditpol.yml

@@ -0,0 +1,71 @@
+name: Windows Audit Policy Cleared via Auditpol
+id: f067f7cf-f41b-4a60-985e-c23e268a13cb
+version: 1
+date: '2025-01-27'
+author: Nasreddine Bencherchali, Splunk
+status: production
+type: TTP
+description: The following analytic identifies the execution of `auditpol.exe` with the "/clear" command-line argument used to clears the audit policy. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity can be significant as it indicates potential defense evasion by adversaries or Red Teams, aiming to limit data that can be leveraged for detections and audits. If confirmed malicious, this behavior could allow attackers to bypass defenses, and plan further attacks, potentially leading to full machine compromise or lateral movement.
+data_source:
+- Sysmon EventID 1
+- Windows Event Log Security 4688
+- CrowdStrike ProcessRollup2
+search: '| tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_auditpol` Processes.process IN ("*/clear*", "*/remove*") AND NOT Processes.process IN ("*/resourceSACL*", "*/?*") by Processes.dest Processes.user Processes.parent_process Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_audit_policy_cleared_via_auditpol_filter`'
+how_to_implement: The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process name, and process original file name. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
+known_false_positives: None identified. Attempts to disable logging should be identified and understood.
+references:
+- https://www.microsoft.com/en-us/security/blog/2021/01/20/deep-dive-into-the-solorigate-second-stage-activation-from-sunburst-to-teardrop-and-raindrop/
+- https://www.cybereason.com/blog/research/prometei-botnet-exploiting-microsoft-exchange-vulnerabilities
+- https://attack.mitre.org/techniques/T1562/002/
+- https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/auditpol-clear
+- https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/auditpol-remove
+drilldown_searches:
+- name: View the detection results for - "$user$" and "$dest$"
+  search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
+  earliest_offset: $info_min_time$
+  latest_offset: $info_max_time$
+- name: View risk events for the last 7 days for - "$user$" and "$dest$"
+  search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$",
+    "$dest$") 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: $info_max_time$
+rba:
+  message: An instance of $parent_process_name$ spawning $process_name$ was identified attempting to clear logging on endpoint $dest$ by user $user$.
+  risk_objects:
+  - field: user
+    type: user
+    score: 16
+  - field: dest
+    type: system
+    score: 16
+  threat_objects:
+  - field: process_name
+    type: process_name
+tags:
+  analytic_story:
+  - Windows Audit Policy Tampering
+  asset_type: Endpoint
+  mitre_attack_id:
+  - T1562.002
+  product:
+  - Splunk Enterprise
+  - Splunk Enterprise Security
+  - Splunk Cloud
+  security_domain: endpoint
+tests:
+- name: True Positive Test - Sysmon
+  attack_data:
+  - data: 
+      https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.002/auditpol_tampering/auditpol_tampering_sysmon.log
+    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
+    sourcetype: XmlWinEventLog
+- name: True Positive Test - Security
+  attack_data:
+  - data: 
+      https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.002/auditpol_tampering/auditpol_tampering_security.log
+    source: XmlWinEventLog:Security
+    sourcetype: XmlWinEventLog

detections/endpoint/windows_audit_policy_disabled_via_auditpol.yml

@@ -0,0 +1,64 @@
+name: Windows Audit Policy Disabled via Auditpol
+id: 14e008e5-6723-4298-b0d4-e95b24e10c18
+version: 1
+date: '2025-01-27'
+author: Nasreddine Bencherchali, Splunk
+status: production
+type: Anomaly
+description: The following analytic identifies the execution of `auditpol.exe` with the "/set" command-line argument in order to disable a specific category or sub-category from the audit policy. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity can be significant as it indicates potential defense evasion by adversaries or Red Teams, aiming to limit data that can be leveraged for detections and audits. If confirmed malicious, this behavior could allow attackers to bypass defenses, and plan further attacks, potentially leading to full machine compromise or lateral movement.
+data_source:
+- Sysmon EventID 1
+- Windows Event Log Security 4688
+- CrowdStrike ProcessRollup2
+search: '| tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_auditpol` Processes.process="*/set*" Processes.process IN ("*/success:*", "*/failure:*") Processes.process="*disable*" AND NOT Processes.process IN ("*/?*", "*/exclude*") by Processes.dest Processes.user Processes.parent_process Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_audit_policy_disabled_via_auditpol_filter`'
+how_to_implement: The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process name, and process original file name. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
+known_false_positives: False positives should be rare, investigate the activity, and apply additional filters when necessary.
+references:
+- https://www.microsoft.com/en-us/security/blog/2021/01/20/deep-dive-into-the-solorigate-second-stage-activation-from-sunburst-to-teardrop-and-raindrop/
+- https://www.cybereason.com/blog/research/prometei-botnet-exploiting-microsoft-exchange-vulnerabilities
+- https://attack.mitre.org/techniques/T1562/002/
+- https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/auditpol-set
+drilldown_searches:
+- name: View the detection results for - "$user$" and "$dest$"
+  search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
+  earliest_offset: $info_min_time$
+  latest_offset: $info_max_time$
+- name: View risk events for the last 7 days for - "$user$" and "$dest$"
+  search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$",
+    "$dest$") 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: $info_max_time$
+rba:
+  message: An instance of $parent_process_name$ spawning $process_name$ with CommandLine $process$ was identified attempting to disable and audit policy category/sub-category on $dest$ by user $user$.
+  risk_objects:
+  - field: user
+    type: user
+    score: 25
+  - field: dest
+    type: system
+    score: 25
+  threat_objects:
+  - field: process_name
+    type: process_name
+tags:
+  analytic_story:
+  - Windows Audit Policy Tampering
+  asset_type: Endpoint
+  mitre_attack_id:
+  - T1562.002
+  product:
+  - Splunk Enterprise
+  - Splunk Enterprise Security
+  - Splunk Cloud
+  security_domain: endpoint
+tests:
+- name: True Positive Test - Sysmon
+  attack_data:
+  - data: 
+      https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.002/auditpol_tampering/auditpol_tampering_sysmon.log
+    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
+    sourcetype: XmlWinEventLog