adding new detection

detections/cloud/azure_ad_user_immutableid_attribute_updated.yml

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+name: Azure AD User ImmutableId Attribute Updated
+id: 0c0badad-4536-4a84-a561-5ff760f3c00e
+version: 1
+date: '2022-09-02'
+author: Mauricio Velazco, Splunk
+type: TTP
+datamodel: []
+description: The following analytic.
+search: ' `azuread` body.operationName="Update user" body.properties.targetResources{}.modifiedProperties{}.displayName=SourceAnchor
+  | rename body.properties.* as *
+  | rename targetResources{}.userPrincipalName as userPrincipalName 
+  | rename initiatedBy.user.userPrincipalName as initiatedBy
+  | rename body.callerIpAddress as callerIpAddress
+  | rename targetResources{}.modifiedProperties{}.newValue as modifiedProperties
+  | stats values(userPrincipalName) values(modifiedProperties) by _time, initiatedBy, callerIpAddress, result, body.operationName
+  | `azure_ad_user_immutableid_attribute_updated_filter`'
+how_to_implement: You must install the latest version of Splunk Add-on for Microsoft Cloud Services from Splunkbase(https://splunkbase.splunk.com/app/3110/#/details). You must be ingesting Azure Active Directory events into your Splunk environment. 
+  Specifically, this analytic leverages the AuditLogs log category.
+known_false_positives: UPDATE_KNOWN_FALSE_POSITIVES
+references:
+- https://docs.microsoft.com/en-us/azure/active-directory/hybrid/plan-connect-design-concepts
+- https://www.mandiant.com/resources/blog/remediation-and-hardening-strategies-for-microsoft-365-to-defend-against-unc2452
+- https://o365blog.com/post/federation-vulnerability/
+- https://www.inversecos.com/2021/11/how-to-detect-azure-active-directory.html
+- https://www.mandiant.com/resources/blog/detecting-microsoft-365-azure-active-directory-backdoors
+- https://attack.mitre.org/techniques/T1098/
+tags:
+  analytic_story:
+  - Azure Active Directory Persistence
+  asset_type: Azure Active Directory
+  cis20:
+  - CIS 3
+  - CIS 5
+  - CIS 16
+  confidence: 90
+  context:
+  - Source:Cloud Data
+  - Stage:Persistence
+  dataset:
+  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1098/azure_ad_set_immutableid/azure-audit.log
+  impact: 50
+  kill_chain_phases:
+  - Installation
+  - Actions on Objectives
+  message: UPDATE message
+  mitre_attack_id:
+  - T1098
+  nist:
+  - DE.CM
+  observable:
+  - name: userPrincipalName
+    type: User
+    role:
+    - Victim
+  - name: initiatedBy
+    type: User
+    role:
+    - Attacker
+  product:
+  - Splunk Enterprise
+  - Splunk Enterprise Security
+  - Splunk Cloud
+  required_fields:
+  - _time
+  risk_score: 45
+  security_domain: threat

tests/cloud/azure_ad_user_immutableid_attribute_updated.test.yml

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+name: Azure AD User ImmutableId Attribute Updated Unit Test
+tests:
+- name: Azure AD User ImmutableId Attribute Updated
+  file: cloud/azure_ad_user_immutableid_attribute_updated.yml
+  pass_condition: '| stats count | where count > 0'
+  earliest_time: -24h
+  latest_time: now
+  attack_data:
+  - file_name: azure-audit.log
+    data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1098/azure_ad_set_immutableid/azure-audit.log
+    source: mscs:azure:eventhub
+    sourcetype: mscs:azure:eventhub
+    update_timestamp: true