NRT Authentication Methods Changed for VIP Users

id: 29e99017-e28d-47be-8b9a-c8c711f8a903
name: NRT Authentication Methods Changed for VIP Users 
description: |
  'Identifies authentication methods being changed for a list of VIP users watchlist. This could be an indication of an attacker adding an auth method to the account so they can have continued access.'
severity: Medium
requiredDataConnectors:
  - connectorId: AzureActiveDirectory
    dataTypes:
      - AuditLogs
tactics:
  - Persistence
relevantTechniques:
  - T1098
tags:
  - AADSecOpsGuide
query: |
  let security_info_actions = dynamic(["User registered security info", "User changed default security info", "User deleted security info", "Admin updated security info", "User reviewed security info", "Admin deleted security info", "Admin registered security info"]);
  let VIPUsers = _GetWatchlist('VIPUsers')
    | extend ["User Principal Name"] = column_ifexists("User Principal Name","")
    | distinct ["User Principal Name"];
  AuditLogs
  | where Category =~ "UserManagement"
  | where ActivityDisplayName in (security_info_actions)
  | extend InitiatingAppName = tostring(InitiatedBy.app.displayName)
  | extend InitiatingAppServicePrincipalId = tostring(InitiatedBy.app.servicePrincipalId)
  | extend InitiatingUserPrincipalName = tostring(InitiatedBy.user.userPrincipalName)
  | extend InitiatingAadUserId = tostring(InitiatedBy.user.id)
  | extend InitiatingIpAddress = tostring(iff(isnotempty(InitiatedBy.user.ipAddress), InitiatedBy.user.ipAddress, InitiatedBy.app.ipAddress))
  | mv-apply TargetResource = TargetResources on 
    (
        where TargetResource.type =~ "User"
        | extend Target = trim(@'"',tolower(tostring(TargetResource.userPrincipalName)))
    )
  | where Target in~ (VIPUsers)
  | summarize Start=min(TimeGenerated), End=max(TimeGenerated), Actions = make_set(ResultReason) by InitiatingUserPrincipalName, InitiatingAadUserId, InitiatingAppName, InitiatingAppServicePrincipalId, InitiatingIpAddress, Result, Target
  | extend TargetName = tostring(split(Target,'@',0)[0]), TargetUPNSuffix = tostring(split(Target,'@',1)[0])
  | extend InitiatedByName = tostring(split(InitiatingUserPrincipalName,'@',0)[0]), InitiatedByUPNSuffix = tostring(split(InitiatingUserPrincipalName,'@',1)[0])
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: Target
      - identifier: Name
        columnName: TargetName
      - identifier: UPNSuffix
        columnName: TargetUPNSuffix
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: InitiatingUserPrincipalName
      - identifier: Name
        columnName: InitiatedByName
      - identifier: UPNSuffix
        columnName: InitiatedByUPNSuffix
  - entityType: Account
    fieldMappings:
      - identifier: AadUserId
        columnName: InitiatingAadUserId
  - entityType: Account
    fieldMappings:
      - identifier: AadUserId
        columnName: InitiatingAppServicePrincipalId
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: InitiatingIpAddress
version: 1.0.6
kind: NRT