Solutions/Threat Intelligence (NEW)/Analytic Rules/IPEntity_W3CIISLog.yaml

id: 888c4736-e604-48eb-b2c7-3462356d9510
name: TI Map IP Entity to W3CIISLog
description: |
  This query maps any IP indicators of compromise (IOCs) from threat intelligence (TI), by searching for matches in W3CIISLog.
severity: Medium
requiredDataConnectors:
  - connectorId: ThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: ThreatIntelligenceTaxii
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: MicrosoftDefenderThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: AzureMonitor(IIS)
    dataTypes:
      - W3CIISLog
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
relevantTechniques:
  - T1071
query: |
  let dt_lookBack = 1h; // Look back 1 hour for W3CIISLog events
  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)
    | where isnotempty(NetworkSourceIP)
    | where TimeGenerated >= ago(ioc_lookBack)
    | 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, "")
    | 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 W3CIISLog events
  IP_Indicators
    | project-reorder *, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, TI_ipEntity
    // Use innerunique to keep performance fast and result set low, as we only need one match to indicate potential malicious activity that needs investigation
    | join kind=innerunique (
        W3CIISLog
        | where TimeGenerated >= ago(dt_lookBack)
        | where isnotempty(cIP)
        | where ipv4_is_private(cIP) == false and cIP !startswith "fe80" and cIP !startswith "::" and cIP !startswith "127."
        | extend W3CIISLog_TimeGenerated = TimeGenerated
    )
    on $left.TI_ipEntity == $right.cIP
    // Filter out W3CIISLog events that occurred after the expiration of the corresponding indicator
    | where W3CIISLog_TimeGenerated < ValidUntil
    // Group the results by IndicatorId and keep the W3CIISLog event with the latest timestamp
    | summarize W3CIISLog_TimeGenerated = arg_max(W3CIISLog_TimeGenerated, *) by Id, cIP
    // Select the desired output fields
    | extend Description = tostring(parse_json(Data).description)
    | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
    | project timestamp = W3CIISLog_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence,
      TI_ipEntity, Computer, sSiteName, cIP, sIP, sPort, csMethod, csUserName, scStatus, scSubStatus, scWin32Status,
     NetworkSourceIP, Type, Url
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: csUserName
  - entityType: Host
    fieldMappings:
      - identifier: HostName
        columnName: Computer
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: cIP
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: Url
version: 1.4.4
kind: Scheduled