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

id: f50280e5-5eb1-4e95-99fd-9d584a987bdd
name: TI map IP entity to OfficeActivity
description: |
  This query maps any IP indicators of compromise (IOCs) from threat intelligence (TI), by searching for matches in OfficeActivity.
severity: Medium
requiredDataConnectors:
  - connectorId: ThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: ThreatIntelligenceTaxii
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: MicrosoftDefenderThreatIntelligence
    dataTypes:
      - ThreatIntelligenceIndicator
  - connectorId: Office365
    dataTypes:
      - OfficeActivity
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
relevantTechniques:
  - T1071
query: |
  let dt_lookBack = 1h; // Look back 1 hour for OfficeActivity events
  let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
  let OfficeActivity_ = materialize(OfficeActivity
    | where isnotempty(ClientIP)
    | where TimeGenerated >= ago(dt_lookBack)
    | extend ClientIPValues = extract_all(@'\[?(::ffff:)?(?P<IPAddress>(\d+\.\d+\.\d+\.\d+)|[^\]%]+)(%\d+)?\]?([-:](?P<Port>\d+))?', dynamic(["IPAddress", "Port"]), ClientIP)[0]
    | extend IPAddress = iff(array_length(ClientIPValues) > 0, tostring(ClientIPValues[0]), '')
    | project-rename OfficeActivity_TimeGenerated = TimeGenerated);
  let ActivityIPs = OfficeActivity_ | summarize IPs = make_list(IPAddress);
  // Fetch threat intelligence indicators related to IP addresses
  let IP_Indicators = materialize(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 = NetworkSourceIP
    | where TI_ipEntity in (ActivityIPs)
    | extend Url = iff(ObservableKey == "url:value", ObservableValue, "")
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id
    | where  IsActive == true and ValidUntil > now()
    | extend Description = tostring(parse_json(Data).description)
    | where Description !contains_cs "State: inactive;" and Description !contains_cs "State: falsepos;");
  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 (OfficeActivity_)
    on $left.TI_ipEntity == $right.IPAddress
  // Filter out OfficeActivity events that occurred after the expiration of the corresponding indicator
  | where OfficeActivity_TimeGenerated < ValidUntil
  // Group the results by IndicatorId and keep the OfficeActivity event with the latest timestamp
  | summarize OfficeActivity_TimeGenerated = arg_max(OfficeActivity_TimeGenerated, *) by Id
  // Select the desired output fields
  | extend Description = tostring(parse_json(Data).description)
  | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
  | project OfficeActivity_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence, TI_ipEntity, ClientIP, UserId, Operation, ResultStatus, RecordType, OfficeObjectId, NetworkSourceIP, Type, Url
  | extend timestamp = OfficeActivity_TimeGenerated, Name = tostring(split(UserId, '@', 0)[0]), UPNSuffix = tostring(split(UserId, '@', 1)[0])
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: UserId
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: TI_ipEntity
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: Url
version: 1.4.5
kind: Scheduled