Solutions/Threat Intelligence (NEW)/Analytic Rules/IPEntity_AzureActivity.yaml

id: 7a0c9989-1618-4126-9290-fb77b976d181
name: TI Map IP Entity to AzureActivity
description: |
  This query maps any IP indicators of compromise (IOCs) from threat intelligence (TI), by searching for matches in AzureActivity.
severity: Medium
requiredDataConnectors:
  - connectorId: ThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: ThreatIntelligenceTaxii
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: AzureActivity
    dataTypes:
      - AzureActivity
  - connectorId: MicrosoftDefenderThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
relevantTechniques:
  - T1071
query: |
  let dt_lookBack = 1h; // Look back 1 hour for AzureActivity logs
  let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
  // Fetch threat intelligence indicators related to IP addresses
  let IP_Indicators = ThreatIntelIndicators
   //extract key part of kv pair
       | extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
       | where isnotempty(IndicatorType) and IndicatorType == "ipv4-addr"
       | extend NetworkSourceIP = toupper(ObservableValue)
       | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
    // Filter out indicators without relevant IP address fields
    | where isnotempty(NetworkSourceIP)
    | where TimeGenerated >= ago(ioc_lookBack)
    // Select the IP entity based on availability of different IP fields
    | extend TI_ipEntity = iff(isnotempty(NetworkSourceIP), NetworkSourceIP, NetworkSourceIP)
    | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)
    | extend Url = iff(ObservableKey == "url:value", ObservableValue, "")
    // Exclude local addresses using the ipv4_is_private operator and filtering out specific address prefixes
    | where ipv4_is_private(TI_ipEntity) == false and  TI_ipEntity !startswith "fe80" and TI_ipEntity !startswith "::" and TI_ipEntity !startswith "127."
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id
    | where IsActive == true and ValidUntil > now();
  // Perform a join between IP indicators and AzureActivity logs to identify potential malicious activity
  IP_Indicators
     | project-reorder *, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, TI_ipEntity
  // using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated
  | join kind=innerunique (
      AzureActivity | where TimeGenerated >= ago(dt_lookBack)
      // renaming time column so it is clear the log this came from
      | extend AzureActivity_TimeGenerated = TimeGenerated
  )
  on $left.TI_ipEntity == $right.CallerIpAddress
  | where AzureActivity_TimeGenerated < ValidUntil
  | summarize AzureActivity_TimeGenerated = arg_max(AzureActivity_TimeGenerated, *) by Id, CallerIpAddress
  | extend Description = tostring(parse_json(Data).description)
  | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
  | project AzureActivity_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence, TI_ipEntity, CallerIpAddress, 
  Caller, OperationNameValue, ActivityStatusValue, CategoryValue, ResourceId, NetworkSourceIP, Type, Url
  | extend timestamp = AzureActivity_TimeGenerated
  | extend Name = iif(Caller has '@', tostring(split(Caller,'@',0)[0]), "")
  | extend UPNSuffix = iif(Caller has '@', tostring(split(Caller,'@',1)[0]), "")
  | extend AadUserId = iif(Caller !has '@', tostring(Caller), "")
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: Caller
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: Account
    fieldMappings:
      - identifier: AadUserId
        columnName: AadUserId
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: CallerIpAddress
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: Url
  - entityType: AzureResource
    fieldMappings:
      - identifier: ResourceId
        columnName: ResourceId
version: 1.4.5
kind: Scheduled