Unauthorized DHCP configuration in the network (Microsoft Defender for IoT)

Status: available
Severity: medium
Time window: 1h
Source: github.com/Azure/Azure-Sentinel

'This alert leverages Defender for IoT to detect an unauthorized DHCP configuration indicating a possible unauthorized device configuration.'

MITRE ATT&CK coverage

Tactic	Techniques
Discovery	`T0842` Network Sniffing

Rule body

id: c52ec521-9188-4a9e-a4cd-34a3dfbc3d27
name: Unauthorized DHCP configuration in the network (Microsoft Defender for IoT)
description: |
  'This alert leverages Defender for IoT to detect an unauthorized DHCP configuration indicating a possible unauthorized device configuration.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: IoT
    dataTypes:
      - SecurityAlert (ASC for IoT)
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Discovery
relevantTechniques:
  - T0842
query: |
  SecurityAlert
  | where ProviderName == "IoTSecurity"
  | where AlertName == "Device Failed to Receive a Dynamic IP Address"
  | extend ExtendedProperties = parse_json(ExtendedProperties)
  | where tostring(ExtendedProperties.isNew) == "True"
  | extend DeviceId = tostring(ExtendedProperties.DeviceId), 
           SourceDeviceAddress = tostring(ExtendedProperties.SourceDeviceAddress), 
           DestDeviceAddress = tostring(ExtendedProperties.DestinationDeviceAddress), 
           RemediationSteps = tostring(parse_json(RemediationSteps)[0]), 
           Protocol = tostring(ExtendedProperties.Protocol), 
           AlertManagementUri = tostring(ExtendedProperties.AlertManagementUri)
  | project
    TimeGenerated,
    DeviceId,
    ProductName,
    ProductComponentName,
    AlertSeverity,
    AlertName,
    Description,
    Protocol,
    SourceDeviceAddress,
    DestDeviceAddress,
    RemediationSteps,
    Tactics,
    Entities,
    VendorOriginalId,
    AlertLink,
    AlertManagementUri,
    Techniques
entityMappings:
sentinelEntitiesMappings:
  - columnName: Entities
eventGroupingSettings:
  aggregationKind: AlertPerResult
customDetails:
  Sensor: DeviceId
  Protocol: Protocol
  VendorOriginalId: VendorOriginalId
  AlertManagementUri: AlertManagementUri
alertDetailsOverride:
  alertDisplayNameFormat: (MDIoT) {{AlertName}}
  alertDescriptionFormat: (MDIoT) {{Description}}
  alertTacticsColumnName: Tactics
  alertSeverityColumnName: AlertSeverity
  alertDynamicProperties: 
    - alertProperty: ProductName
      value: ProductName
    - alertProperty: RemediationSteps
      value: RemediationSteps
    - alertProperty: Techniques
      value: Techniques
    - alertProperty: ProductComponentName
      value: ProductComponentName
    - alertProperty: AlertLink
      value: AlertLink
version: 1.0.3
kind: Scheduled

Stages and Predicates

Stage 1: `source`

SecurityAlert

Stage 2: `where`

| where ProviderName == "IoTSecurity"

Stage 3: `where`

| where AlertName == "Device Failed to Receive a Dynamic IP Address"

Stage 4: `extend`

| extend ExtendedProperties = parse_json(ExtendedProperties)

Stage 5: `where`

| where tostring(ExtendedProperties.isNew) == "True"

Stage 6: `extend`

| extend DeviceId = tostring(ExtendedProperties.DeviceId), 
         SourceDeviceAddress = tostring(ExtendedProperties.SourceDeviceAddress), 
         DestDeviceAddress = tostring(ExtendedProperties.DestinationDeviceAddress), 
         RemediationSteps = tostring(parse_json(RemediationSteps)[0]), 
         Protocol = tostring(ExtendedProperties.Protocol), 
         AlertManagementUri = tostring(ExtendedProperties.AlertManagementUri)

Stage 7: `project`

| project
  TimeGenerated,
  DeviceId,
  ProductName,
  ProductComponentName,
  AlertSeverity,
  AlertName,
  Description,
  Protocol,
  SourceDeviceAddress,
  DestDeviceAddress,
  RemediationSteps,
  Tactics,
  Entities,
  VendorOriginalId,
  AlertLink,
  AlertManagementUri,
  Techniques

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`AlertName`	eq	`Device Failed to Receive a Dynamic IP Address`	`field:"AlertName" kind:eq value:"Device Failed to Receive a Dynamic IP Address"`
`ProviderName`	eq	`IoTSecurity`	`field:"ProviderName" kind:eq value:"IoTSecurity"`
`isNew`	eq	`True` transforms: `tostring`	`field:"isNew" kind:eq value:"True"`

Output fields

These fields are emitted when the rule matches.

Field	Source
`AlertLink`	`project`
`AlertManagementUri`	`project`
`AlertName`	`project`
`AlertSeverity`	`project`
`Description`	`project`
`DestDeviceAddress`	`project`
`DeviceId`	`project`
`Entities`	`project`
`ProductComponentName`	`project`
`ProductName`	`project`
`Protocol`	`project`
`RemediationSteps`	`project`
`SourceDeviceAddress`	`project`
`Tactics`	`project`
`Techniques`	`project`
`TimeGenerated`	`project`
`VendorOriginalId`	`project`

Unauthorized DHCP configuration in the network (Microsoft Defender for IoT)

MITRE ATT&CK coverage

Rule body

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: extend

Stage 5: where

Stage 6: extend

Stage 7: project