TI Map IP entity to AWSCloudTrail

Original query, unchanged.

let dt_lookBack = 1h; // Look back 1 hour for AWSCloudTrail 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 IndicatorType in ("ipv4-addr", "ipv6-addr", "network-traffic")
      | extend NetworkSourceIP = toupper(ObservableValue)
      | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
  // Filter out indicators without relevant IP address fields
  | 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, ObservableValue
  | where IsActive and (ValidUntil > now() or isempty(ValidUntil));
// Perform a join between IP indicators and AWSCloudTrail logs to identify potential malicious activity
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 (
      AWSCloudTrail
      | where TimeGenerated >= ago(dt_lookBack)
      | extend AWSCloudTrail_TimeGenerated = TimeGenerated // Rename time column for clarity
    )
    on $left.TI_ipEntity == $right.SourceIpAddress
  // Filter out logs that occurred after the expiration of the corresponding indicator
  | where AWSCloudTrail_TimeGenerated < ValidUntil
  // Group the results by IndicatorId and SourceIpAddress, and keep the log entry with the latest timestamp
  | summarize AWSCloudTrail_TimeGenerated = arg_max(AWSCloudTrail_TimeGenerated, *) by Id, SourceIpAddress
  // Select the desired output fields
  | extend Description = tostring(parse_json(Data).description)
  | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
  | project AWSCloudTrail_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence,
    TI_ipEntity, EventName, EventTypeName, UserIdentityAccountId, UserIdentityPrincipalid, UserIdentityUserName, SourceIpAddress,
    NetworkSourceIP, Url
  // Rename the timestamp field
  | extend timestamp = AWSCloudTrail_TimeGenerated