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Ida09a0b8e-30fe-4ebf-94a0-cffe50f579cd
RulenameUser State changed from Guest to Member
DescriptionDetects when a guest account in a tenant is converted to a member of the tenant.

Monitoring guest accounts and the access they are provided is important to detect potential account abuse.

Accounts converted to members should be investigated to ensure the activity was legitimate.

Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#monitoring-for-failed-unusual-sign-ins
SeverityMedium
TacticsPersistence
TechniquesT1098
Required data connectorsAzureActiveDirectory
KindScheduled
Query frequency1d
Query period1d
Trigger threshold0
Trigger operatorgt
Source Urihttps://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/UserStatechangedfromGuesttoMember.yaml
Version1.1.0
Arm templatea09a0b8e-30fe-4ebf-94a0-cffe50f579cd.json
Deploy To Azure
AuditLogs
  | where OperationName =~ "Update user"
  | where Result =~ "success"
  | mv-expand TargetResources
  | mv-expand TargetResources.modifiedProperties
  | where TargetResources_modifiedProperties.displayName =~ "TargetId.UserType"
  | extend UpdatingAppName = tostring(parse_json(tostring(InitiatedBy.app)).displayName)
  | extend UpdatingServicePrincipalId = tostring(parse_json(tostring(InitiatedBy.app)).servicePrincipalId)
  | extend UpdatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
  | extend UpdatingUserAadUserId = tostring(parse_json(tostring(InitiatedBy.user)).id)
  | extend UpdatingUserIPAddress = tostring(parse_json(tostring(InitiatedBy.user)).ipAddress)
  | extend UpdatingUser = iif(isnotempty(UpdatingServicePrincipalId), UpdatingServicePrincipalId, UpdatingUserPrincipalName)
  | extend UpdatedUserPrincipalName = tostring(TargetResources.userPrincipalName)
  | project-reorder TimeGenerated, UpdatedUserPrincipalName, UpdatingUser
  | where parse_json(tostring(TargetResources_modifiedProperties.newValue)) =~ "\"Member\"" and parse_json(tostring(TargetResources_modifiedProperties.oldValue)) =~ "\"Guest\""
  | extend InitiatingAccountName = tostring(split(UpdatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(UpdatingUserPrincipalName, "@")[1])
  | extend TargetAccountName = tostring(split(UpdatedUserPrincipalName, "@")[0]), TargetAccountUPNSuffix = tostring(split(UpdatedUserPrincipalName, "@")[1])
tactics:
- Persistence
triggerThreshold: 0
relevantTechniques:
- T1098
queryPeriod: 1d
name: User State changed from Guest to Member
description: |
  'Detects when a guest account in a tenant is converted to a member of the tenant.
    Monitoring guest accounts and the access they are provided is important to detect potential account abuse.
    Accounts converted to members should be investigated to ensure the activity was legitimate.
    Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#monitoring-for-failed-unusual-sign-ins'
metadata:
  source:
    kind: Community
  support:
    tier: Community
  author:
    name: Microsoft Security Research
  categories:
    domains:
    - Security - Others
    - Identity
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/UserStatechangedfromGuesttoMember.yaml
kind: Scheduled
entityMappings:
- fieldMappings:
  - columnName: UpdatingAppName
    identifier: Name
  - columnName: UpdatingServicePrincipalId
    identifier: AadUserId
  entityType: Account
- fieldMappings:
  - columnName: UpdatingUserPrincipalName
    identifier: FullName
  - columnName: InitiatingAccountName
    identifier: Name
  - columnName: InitiatingAccountUPNSuffix
    identifier: UPNSuffix
  entityType: Account
- fieldMappings:
  - columnName: UpdatingUserAadUserId
    identifier: AadUserId
  entityType: Account
- fieldMappings:
  - columnName: UpdatedUserPrincipalName
    identifier: FullName
  - columnName: TargetAccountName
    identifier: Name
  - columnName: TargetAccountUPNSuffix
    identifier: UPNSuffix
  entityType: Account
- fieldMappings:
  - columnName: UpdatingUserIPAddress
    identifier: Address
  entityType: IP
tags:
- AADSecOpsGuide
triggerOperator: gt
id: a09a0b8e-30fe-4ebf-94a0-cffe50f579cd
severity: Medium
version: 1.1.0
requiredDataConnectors:
- connectorId: AzureActiveDirectory
  dataTypes:
  - AuditLogs
query: |
  AuditLogs
    | where OperationName =~ "Update user"
    | where Result =~ "success"
    | mv-expand TargetResources
    | mv-expand TargetResources.modifiedProperties
    | where TargetResources_modifiedProperties.displayName =~ "TargetId.UserType"
    | extend UpdatingAppName = tostring(parse_json(tostring(InitiatedBy.app)).displayName)
    | extend UpdatingServicePrincipalId = tostring(parse_json(tostring(InitiatedBy.app)).servicePrincipalId)
    | extend UpdatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)
    | extend UpdatingUserAadUserId = tostring(parse_json(tostring(InitiatedBy.user)).id)
    | extend UpdatingUserIPAddress = tostring(parse_json(tostring(InitiatedBy.user)).ipAddress)
    | extend UpdatingUser = iif(isnotempty(UpdatingServicePrincipalId), UpdatingServicePrincipalId, UpdatingUserPrincipalName)
    | extend UpdatedUserPrincipalName = tostring(TargetResources.userPrincipalName)
    | project-reorder TimeGenerated, UpdatedUserPrincipalName, UpdatingUser
    | where parse_json(tostring(TargetResources_modifiedProperties.newValue)) =~ "\"Member\"" and parse_json(tostring(TargetResources_modifiedProperties.oldValue)) =~ "\"Guest\""
    | extend InitiatingAccountName = tostring(split(UpdatingUserPrincipalName, "@")[0]), InitiatingAccountUPNSuffix = tostring(split(UpdatingUserPrincipalName, "@")[1])
    | extend TargetAccountName = tostring(split(UpdatedUserPrincipalName, "@")[0]), TargetAccountUPNSuffix = tostring(split(UpdatedUserPrincipalName, "@")[1])
queryFrequency: 1d
{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/a09a0b8e-30fe-4ebf-94a0-cffe50f579cd')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/a09a0b8e-30fe-4ebf-94a0-cffe50f579cd')]",
      "properties": {
        "alertRuleTemplateName": "a09a0b8e-30fe-4ebf-94a0-cffe50f579cd",
        "customDetails": null,
        "description": "'Detects when a guest account in a tenant is converted to a member of the tenant.\n  Monitoring guest accounts and the access they are provided is important to detect potential account abuse.\n  Accounts converted to members should be investigated to ensure the activity was legitimate.\n  Ref: https://docs.microsoft.com/azure/active-directory/fundamentals/security-operations-user-accounts#monitoring-for-failed-unusual-sign-ins'\n",
        "displayName": "User State changed from Guest to Member",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "UpdatingAppName",
                "identifier": "Name"
              },
              {
                "columnName": "UpdatingServicePrincipalId",
                "identifier": "AadUserId"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "UpdatingUserPrincipalName",
                "identifier": "FullName"
              },
              {
                "columnName": "InitiatingAccountName",
                "identifier": "Name"
              },
              {
                "columnName": "InitiatingAccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "UpdatingUserAadUserId",
                "identifier": "AadUserId"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "UpdatedUserPrincipalName",
                "identifier": "FullName"
              },
              {
                "columnName": "TargetAccountName",
                "identifier": "Name"
              },
              {
                "columnName": "TargetAccountUPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "UpdatingUserIPAddress",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/AuditLogs/UserStatechangedfromGuesttoMember.yaml",
        "query": "AuditLogs\n  | where OperationName =~ \"Update user\"\n  | where Result =~ \"success\"\n  | mv-expand TargetResources\n  | mv-expand TargetResources.modifiedProperties\n  | where TargetResources_modifiedProperties.displayName =~ \"TargetId.UserType\"\n  | extend UpdatingAppName = tostring(parse_json(tostring(InitiatedBy.app)).displayName)\n  | extend UpdatingServicePrincipalId = tostring(parse_json(tostring(InitiatedBy.app)).servicePrincipalId)\n  | extend UpdatingUserPrincipalName = tostring(parse_json(tostring(InitiatedBy.user)).userPrincipalName)\n  | extend UpdatingUserAadUserId = tostring(parse_json(tostring(InitiatedBy.user)).id)\n  | extend UpdatingUserIPAddress = tostring(parse_json(tostring(InitiatedBy.user)).ipAddress)\n  | extend UpdatingUser = iif(isnotempty(UpdatingServicePrincipalId), UpdatingServicePrincipalId, UpdatingUserPrincipalName)\n  | extend UpdatedUserPrincipalName = tostring(TargetResources.userPrincipalName)\n  | project-reorder TimeGenerated, UpdatedUserPrincipalName, UpdatingUser\n  | where parse_json(tostring(TargetResources_modifiedProperties.newValue)) =~ \"\\\"Member\\\"\" and parse_json(tostring(TargetResources_modifiedProperties.oldValue)) =~ \"\\\"Guest\\\"\"\n  | extend InitiatingAccountName = tostring(split(UpdatingUserPrincipalName, \"@\")[0]), InitiatingAccountUPNSuffix = tostring(split(UpdatingUserPrincipalName, \"@\")[1])\n  | extend TargetAccountName = tostring(split(UpdatedUserPrincipalName, \"@\")[0]), TargetAccountUPNSuffix = tostring(split(UpdatedUserPrincipalName, \"@\")[1])\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Persistence"
        ],
        "tags": [
          "AADSecOpsGuide"
        ],
        "techniques": [
          "T1098"
        ],
        "templateVersion": "1.1.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}