PLC Stop Command (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 PLC stop commands which could indicate improper configuration or malicious activity on the network such as a threat manipulating PLC programming to affect the function of the network.'

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T0858` Change Operating Mode
Evasion	`T0858` Change Operating Mode

Rule body

id: a7d3f642-15d8-4e83-99ee-83ca3352525d
name: PLC Stop Command (Microsoft Defender for IoT)
description: |
  'This alert leverages Defender for IoT to detect PLC stop commands which could indicate improper configuration or malicious activity on the network such as a threat manipulating PLC programming to affect the function of the network.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: IoT
    dataTypes:
      - SecurityAlert (ASC for IoT)
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - DefenseEvasion
relevantTechniques:
  - T0858
query: |
  let alertList = dynamic(["Controller Reset", "An S7 Stop PLC Command was Sent", "Controller Stop", "Excessive Restart Rate of an Outstation", "GE SRTP Stop PLC Command was Sent", "Outstation Restarted", "Outstation Restarts Frequently", "Profinet Device Factory Reset", "Slave Device Unrecoverable Failure", "Suspicion of Hardware Problems in Outstation"]);
  SecurityAlert
  | where ProviderName == "IoTSecurity"
  | where AlertName has_any (alertList) 
  | 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

Let binding: `alertList` used in Stage 3

let alertList = dynamic(["Controller Reset", "An S7 Stop PLC Command was Sent", "Controller Stop", "Excessive Restart Rate of an Outstation", "GE SRTP Stop PLC Command was Sent", "Outstation Restarted", "Outstation Restarts Frequently", "Profinet Device Factory Reset", "Slave Device Unrecoverable Failure", "Suspicion of Hardware Problems in Outstation"]);

Stage 1: `source`

SecurityAlert

Stage 2: `where`

| where ProviderName == "IoTSecurity"

Stage 3: `where`

| where AlertName has_any (alertList)

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`	match	`An S7 Stop PLC Command was Sent` transforms: `term` `Controller Reset` transforms: `term` `Controller Stop` transforms: `term` `Excessive Restart Rate of an Outstation` transforms: `term` `GE SRTP Stop PLC Command was Sent` transforms: `term` `Outstation Restarted` transforms: `term` `Outstation Restarts Frequently` transforms: `term` `Profinet Device Factory Reset` transforms: `term` `Slave Device Unrecoverable Failure` transforms: `term` `Suspicion of Hardware Problems in Outstation` transforms: `term`	`field:"AlertName" kind:match`
`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`

PLC Stop Command (Microsoft Defender for IoT)

MITRE ATT&CK coverage

Rule body

Stages and Predicates

Let binding: alertList used in Stage 3

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: extend

Stage 5: where

Stage 6: extend

Stage 7: project