From 3399bc4288baacceea48b1bde71d4e5d2a7f51f0 Mon Sep 17 00:00:00 2001
From: dluxtron <106139814+dluxtron@users.noreply.github.com>
Date: Thu, 8 Sep 2022 20:45:45 +1000
Subject: [PATCH] Adding DSRM Account Changes

---
 detections/endpoint/dsrm_account_changes.yml | 77 ++++++++++++++++++++
 detections/endpoint/dsrm_password_reset.yml  |  2 +-
 tests/endpoint/dsrm_account_changes.test.yml | 13 ++++
 3 files changed, 91 insertions(+), 1 deletion(-)
 create mode 100644 detections/endpoint/dsrm_account_changes.yml
 create mode 100644 tests/endpoint/dsrm_account_changes.test.yml

diff --git a/detections/endpoint/dsrm_account_changes.yml b/detections/endpoint/dsrm_account_changes.yml
new file mode 100644
index 0000000000..9294562e8d
--- /dev/null
+++ b/detections/endpoint/dsrm_account_changes.yml
@@ -0,0 +1,77 @@
+name: DSRM Account Changes
+id: 08cb291e-ea77-48e8-a95a-0799319bf056
+version: 1
+date: '2022-09-08'
+author: Dean Luxton
+type: TTP
+datamodel:
+- Endpoint
+description: Aside from being used to promote genuine domain controllers, the DSRM (Directory Services Restore Mode)
+  account can be used to persist within a Domain. A DC can be configured to allow the DSRM account to logon & be
+ used in the same way as a local administrator account. This detection is looking for alterations to the behaviour 
+ of the account via registry.  
+search: '| tstats `security_content_summariesonly` min(_time) as _time from datamodel=Endpoint.Registry
+  where Registry.registry_path= "*\\System\\CurrentControlSet\\Control\\Lsa\\DSRMAdminLogonBehavior"
+  Registry.registry_value_data IN ("*1","*2") by Registry.action Registry.registry_path
+  Registry.registry_value_data Registry.registry_value_type Registry.process_guid
+  | `drop_dm_object_name(Registry)`
+  | join type=outer process_guid [| tstats `security_content_summariesonly` count
+  FROM datamodel=Endpoint.Processes by Processes.user Processes.process_name Processes.process
+  Processes.dest Processes.parent_process_name Processes.parent_process Processes.process_guid
+  | `drop_dm_object_name(Processes)`]
+  | table _time action dest user parent_process_name parent_process process_name process
+  process_guid registry_path registry_value_data registry_value_type | `dsrm_account_changes_filter`'
+how_to_implement: To successfully implement this search, you must be ingesting data
+  that records registry activity from your hosts to populate the endpoint data model
+  in the registry node. This is typically populated via endpoint detection-and-response
+  product, such as Carbon Black or endpoint data sources, such as Sysmon. The data
+  used for this search is typically generated via logs that report reads and writes
+  to the registry.
+known_false_positives: Disaster recovery events. 
+references:
+- https://adsecurity.org/?p=1714
+tags:
+  analytic_story:
+  - Domain Controller Attacks
+  - Windows Registry Abuse
+  - Windows Persistence Techniques
+  asset_type: Endpoint
+  cis20:
+  - CIS 3
+  - CIS 5
+  - CIS 16
+  confidence: 100
+  context:
+  - Source:Endpoint
+  - Stage:Persistence 
+  dataset:
+  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1098/dsrm_account/windows-security-xml.log
+  impact: 100
+  kill_chain_phases:
+  - Actions on Objectives
+  message: DSRM Account Changes Initiated on $dest$ by $user$
+  mitre_attack_id:
+  - T1098
+  nist:
+  - DE.CM
+  observable:
+  - name: user
+    type: User
+    role:
+    - Victim
+  - name: dest
+    type: Hostname
+    role:
+    - Victim
+  product:
+  - Splunk Enterprise
+  - Splunk Enterprise Security
+  - Splunk Cloud
+  required_fields:
+  - _time
+  - Registry.registry_value_data
+  - Registry.registry_path
+  - Registry.dest
+  - Registry.user
+  risk_score: 100
+  security_domain: endpoint
diff --git a/detections/endpoint/dsrm_password_reset.yml b/detections/endpoint/dsrm_password_reset.yml
index eb29b0161f..4627c96c13 100644
--- a/detections/endpoint/dsrm_password_reset.yml
+++ b/detections/endpoint/dsrm_password_reset.yml
@@ -31,7 +31,7 @@ tags:
   confidence: 100
   context:
   - Source:Endpoint
-  - Stage:Defense Evasion
+  - Stage:Persistence
   dataset:
   - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1098/dsrm_account/windows-security-xml.log
   impact: 100
diff --git a/tests/endpoint/dsrm_account_changes.test.yml b/tests/endpoint/dsrm_account_changes.test.yml
new file mode 100644
index 0000000000..b4a3c000e9
--- /dev/null
+++ b/tests/endpoint/dsrm_account_changes.test.yml
@@ -0,0 +1,13 @@
+name: DSRM Account Changes Unit Test
+tests:
+- name: DSRM Account Changes
+  file: endpoint/dsrm_account_changes.yml
+  pass_condition: '| stats count | where count > 0'
+  earliest_time: -24h
+  latest_time: now
+  attack_data:
+  - file_name: windows-sysmon.log
+    data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1098/dsrm_account/windows-sysmon.log
+    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
+    sourcetype: xmlwineventlog
+    update_timestamp: true