Suspicious Entra ID Joined Device Update

AuditLogs
| where OperationName =~ "Update device"
| mv-apply TargetResource=TargetResources on (
    where TargetResource.type =~ "Device"
    | extend ModifiedProperties = TargetResource.modifiedProperties
    | extend DeviceId = TargetResource.id)
| mv-apply Prop=ModifiedProperties on ( 
    where Prop.displayName =~ "CloudDisplayName"
    | extend OldName = Prop.oldValue 
    | extend NewName = Prop.newValue)
| mv-apply Prop=ModifiedProperties on ( 
    where Prop.displayName =~ "IsCompliant"
    | extend OldComplianceState = Prop.oldValue  
    | extend NewComplianceState = Prop.newValue)
| mv-apply Prop=ModifiedProperties on ( 
    where Prop.displayName =~ "TargetId.DeviceTrustType"
    | extend OldTrustType = Prop.oldValue  
    | extend NewTrustType = Prop.newValue)
| mv-apply Prop=ModifiedProperties on ( 
    where Prop.displayName =~ "Included Updated Properties" 
    | extend UpdatedProperties = Prop.newValue)
| extend OldDeviceName = tostring(parse_json(tostring(OldName))[0])
| extend NewDeviceName = tostring(parse_json(tostring(NewName))[0])
| extend OldComplianceState = tostring(parse_json(tostring(OldComplianceState))[0])
| extend NewComplianceState = tostring(parse_json(tostring(NewComplianceState))[0])
| extend InitiatedByUser = tostring(iff(isnotempty(InitiatedBy.user.userPrincipalName),InitiatedBy.user.userPrincipalName, InitiatedBy.app.displayName))
| extend UpdatedPropertiesCount = array_length(split(UpdatedProperties, ','))
| where OldDeviceName != NewDeviceName
| where OldComplianceState =~ 'true' and NewComplianceState =~ 'false'
// Most common is transferring from AAD Registered to AAD Joined - we just want AAD Joined devices
| where NewTrustType == '"AzureAd"' and OldTrustType != '"Workplace"'
// We can modify this value to tune FPs - more properties changed about the device beyond its name the more suspicious it could be
| where UpdatedPropertiesCount > 1
| project-reorder TimeGenerated, DeviceId, NewDeviceName, OldDeviceName, NewComplianceState, InitiatedByUser, AADOperationType, OldTrustType, NewTrustType, UpdatedProperties, UpdatedPropertiesCount

OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/SuspiciousAADJoinedDeviceUpdate.yaml
entityMappings:
- fieldMappings:
  - identifier: HostName
    columnName: NewDeviceName
  entityType: Host
- fieldMappings:
  - identifier: HostName
    columnName: OldDeviceName
  entityType: Host
- fieldMappings:
  - identifier: AzureID
    columnName: DeviceId
  entityType: Host
- fieldMappings:
  - identifier: AadUserId
    columnName: InitiatedByUser
  entityType: Account
alertDetailsOverride:
  alertDisplayNameFormat: Suspicious AAD Joined Device Update {{OldDeviceName}} renamed to {{NewDeviceName}} and {{UpdatedPropertiesCount}} properties changed
  alertDescriptionFormat: |
    This query looks for suspicious updates to an Microsoft Entra ID joined device where the device name is changed and the device falls out of compliance.
    In this case {{OldDeviceName}} was renamed to {{NewDeviceName}} and {{UpdatedPropertiesCount}} properties were changed.
    This could occur when a threat actor steals a Device ticket from an Autopilot provisioned device and uses it to AAD Join a new  device.
    Ref: https://dirkjanm.io/assets/raw/Insomnihack%20Breaking%20and%20fixing%20Azure%20AD%20device%20identity%20security.pdf    
kind: Scheduled
query: |
  AuditLogs
  | where OperationName =~ "Update device"
  | mv-apply TargetResource=TargetResources on (
      where TargetResource.type =~ "Device"
      | extend ModifiedProperties = TargetResource.modifiedProperties
      | extend DeviceId = TargetResource.id)
  | mv-apply Prop=ModifiedProperties on ( 
      where Prop.displayName =~ "CloudDisplayName"
      | extend OldName = Prop.oldValue 
      | extend NewName = Prop.newValue)
  | mv-apply Prop=ModifiedProperties on ( 
      where Prop.displayName =~ "IsCompliant"
      | extend OldComplianceState = Prop.oldValue  
      | extend NewComplianceState = Prop.newValue)
  | mv-apply Prop=ModifiedProperties on ( 
      where Prop.displayName =~ "TargetId.DeviceTrustType"
      | extend OldTrustType = Prop.oldValue  
      | extend NewTrustType = Prop.newValue)
  | mv-apply Prop=ModifiedProperties on ( 
      where Prop.displayName =~ "Included Updated Properties" 
      | extend UpdatedProperties = Prop.newValue)
  | extend OldDeviceName = tostring(parse_json(tostring(OldName))[0])
  | extend NewDeviceName = tostring(parse_json(tostring(NewName))[0])
  | extend OldComplianceState = tostring(parse_json(tostring(OldComplianceState))[0])
  | extend NewComplianceState = tostring(parse_json(tostring(NewComplianceState))[0])
  | extend InitiatedByUser = tostring(iff(isnotempty(InitiatedBy.user.userPrincipalName),InitiatedBy.user.userPrincipalName, InitiatedBy.app.displayName))
  | extend UpdatedPropertiesCount = array_length(split(UpdatedProperties, ','))
  | where OldDeviceName != NewDeviceName
  | where OldComplianceState =~ 'true' and NewComplianceState =~ 'false'
  // Most common is transferring from AAD Registered to AAD Joined - we just want AAD Joined devices
  | where NewTrustType == '"AzureAd"' and OldTrustType != '"Workplace"'
  // We can modify this value to tune FPs - more properties changed about the device beyond its name the more suspicious it could be
  | where UpdatedPropertiesCount > 1
  | project-reorder TimeGenerated, DeviceId, NewDeviceName, OldDeviceName, NewComplianceState, InitiatedByUser, AADOperationType, OldTrustType, NewTrustType, UpdatedProperties, UpdatedPropertiesCount  
triggerOperator: gt
version: 1.0.2
queryPeriod: 1d
name: Suspicious Entra ID Joined Device Update
severity: Medium
relevantTechniques:
- T1528
requiredDataConnectors:
- dataTypes:
  - AuditLogs
  connectorId: AzureActiveDirectory
triggerThreshold: 0
tactics:
- CredentialAccess
queryFrequency: 1d
id: 3a3c6835-0086-40ca-b033-a93bf26d878f
status: Available
description: |
  'This query looks for suspicious updates to an Microsoft Entra ID joined device where the device name is changed and the device falls out of compliance.
  This could occur when a threat actor updates the details of an Autopilot provisioned device using a stolen device ticket, in order to access certificates and keys.
  Ref: https://dirkjanm.io/assets/raw/Insomnihack%20Breaking%20and%20fixing%20Azure%20AD%20device%20identity%20security.pdf'  

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/3a3c6835-0086-40ca-b033-a93bf26d878f')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/3a3c6835-0086-40ca-b033-a93bf26d878f')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "This query looks for suspicious updates to an Microsoft Entra ID joined device where the device name is changed and the device falls out of compliance.\nIn this case {{OldDeviceName}} was renamed to {{NewDeviceName}} and {{UpdatedPropertiesCount}} properties were changed.\nThis could occur when a threat actor steals a Device ticket from an Autopilot provisioned device and uses it to AAD Join a new  device.\nRef: https://dirkjanm.io/assets/raw/Insomnihack%20Breaking%20and%20fixing%20Azure%20AD%20device%20identity%20security.pdf\n",
          "alertDisplayNameFormat": "Suspicious AAD Joined Device Update {{OldDeviceName}} renamed to {{NewDeviceName}} and {{UpdatedPropertiesCount}} properties changed"
        },
        "alertRuleTemplateName": "3a3c6835-0086-40ca-b033-a93bf26d878f",
        "customDetails": null,
        "description": "'This query looks for suspicious updates to an Microsoft Entra ID joined device where the device name is changed and the device falls out of compliance.\nThis could occur when a threat actor updates the details of an Autopilot provisioned device using a stolen device ticket, in order to access certificates and keys.\nRef: https://dirkjanm.io/assets/raw/Insomnihack%20Breaking%20and%20fixing%20Azure%20AD%20device%20identity%20security.pdf'\n",
        "displayName": "Suspicious Entra ID Joined Device Update",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "NewDeviceName",
                "identifier": "HostName"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "OldDeviceName",
                "identifier": "HostName"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "DeviceId",
                "identifier": "AzureID"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "InitiatedByUser",
                "identifier": "AadUserId"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Microsoft Entra ID/Analytic Rules/SuspiciousAADJoinedDeviceUpdate.yaml",
        "query": "AuditLogs\n| where OperationName =~ \"Update device\"\n| mv-apply TargetResource=TargetResources on (\n    where TargetResource.type =~ \"Device\"\n    | extend ModifiedProperties = TargetResource.modifiedProperties\n    | extend DeviceId = TargetResource.id)\n| mv-apply Prop=ModifiedProperties on ( \n    where Prop.displayName =~ \"CloudDisplayName\"\n    | extend OldName = Prop.oldValue \n    | extend NewName = Prop.newValue)\n| mv-apply Prop=ModifiedProperties on ( \n    where Prop.displayName =~ \"IsCompliant\"\n    | extend OldComplianceState = Prop.oldValue  \n    | extend NewComplianceState = Prop.newValue)\n| mv-apply Prop=ModifiedProperties on ( \n    where Prop.displayName =~ \"TargetId.DeviceTrustType\"\n    | extend OldTrustType = Prop.oldValue  \n    | extend NewTrustType = Prop.newValue)\n| mv-apply Prop=ModifiedProperties on ( \n    where Prop.displayName =~ \"Included Updated Properties\" \n    | extend UpdatedProperties = Prop.newValue)\n| extend OldDeviceName = tostring(parse_json(tostring(OldName))[0])\n| extend NewDeviceName = tostring(parse_json(tostring(NewName))[0])\n| extend OldComplianceState = tostring(parse_json(tostring(OldComplianceState))[0])\n| extend NewComplianceState = tostring(parse_json(tostring(NewComplianceState))[0])\n| extend InitiatedByUser = tostring(iff(isnotempty(InitiatedBy.user.userPrincipalName),InitiatedBy.user.userPrincipalName, InitiatedBy.app.displayName))\n| extend UpdatedPropertiesCount = array_length(split(UpdatedProperties, ','))\n| where OldDeviceName != NewDeviceName\n| where OldComplianceState =~ 'true' and NewComplianceState =~ 'false'\n// Most common is transferring from AAD Registered to AAD Joined - we just want AAD Joined devices\n| where NewTrustType == '\"AzureAd\"' and OldTrustType != '\"Workplace\"'\n// We can modify this value to tune FPs - more properties changed about the device beyond its name the more suspicious it could be\n| where UpdatedPropertiesCount > 1\n| project-reorder TimeGenerated, DeviceId, NewDeviceName, OldDeviceName, NewComplianceState, InitiatedByUser, AADOperationType, OldTrustType, NewTrustType, UpdatedProperties, UpdatedPropertiesCount\n",
        "queryFrequency": "P1D",
        "queryPeriod": "P1D",
        "severity": "Medium",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CredentialAccess"
        ],
        "techniques": [
          "T1528"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}