TI map IP entity to AzureNetworkAnalytics_CL (NSG Flow Logs)

Original query, unchanged.

let dt_lookBack = 1h; // Look back 1 hour for AzureNetworkAnalytics_CL logs
let ioc_lookBack = 14d; // Look back 14 days for threat intelligence indicators
// Fetch threat intelligence indicators related to IP addresses
let IP_Indicators = ThreatIntelligenceIndicator
  | where isnotempty(NetworkIP) or isnotempty(EmailSourceIpAddress) or isnotempty(NetworkDestinationIP) or isnotempty(NetworkSourceIP)
  | where TimeGenerated >= ago(ioc_lookBack)
  | extend TI_ipEntity = iff(isnotempty(NetworkIP), NetworkIP, NetworkDestinationIP)
  | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(NetworkSourceIP), NetworkSourceIP, TI_ipEntity)
  | extend TI_ipEntity = iff(isempty(TI_ipEntity) and isnotempty(EmailSourceIpAddress), EmailSourceIpAddress, TI_ipEntity)
  | 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 IndicatorId
  | where Active == true and ExpirationDateTime > now();
// Perform a join between IP indicators and AzureNetworkAnalytics_CL logs for NSG Flow information
IP_Indicators
  // 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 (
      AzureNetworkAnalytics_CL
      | where TimeGenerated >= ago(dt_lookBack)
      | extend AzureNetworkAnalytics_CL_TimeGenerated = TimeGenerated
      | extend PIPs = split(PublicIPs_s, '|', 0)
      | extend PIP = tostring(PIPs[0])
  )
  on $left.TI_ipEntity == $right.PIP
  // Filter out logs that occurred after the expiration of the corresponding indicator
  | where AzureNetworkAnalytics_CL_TimeGenerated < ExpirationDateTime
  // Filter out NSG Flow logs that are not allowed (FlowStatus_s == "A")
  | where FlowStatus_s == "A"
  // Group the results by IndicatorId and PIP (Public IP), and keep the log entry with the latest timestamp
  | summarize AzureNetworkAnalytics_CL_TimeGenerated = arg_max(AzureNetworkAnalytics_CL_TimeGenerated, *) by IndicatorId, PIP
  // Select the desired output fields
  | project AzureNetworkAnalytics_CL_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore,
    TI_ipEntity, Computer, FlowDirection_s, FlowStatus_s, FlowType_s, SrcPublicIPs_s, DestPublicIPs_s, PublicIPs_s, L7Protocol_s, DestPort_d, NetworkIP, NetworkDestinationIP, NetworkSourceIP, EmailSourceIpAddress, Type
  // Extract hostname and DNS domain from the Computer field
  | extend HostName = tostring(split(Computer, '.', 0)[0]), DnsDomain = tostring(strcat_array(array_slice(split(Computer, '.'), 1, -1), '.'))
  // Rename the timestamp field
  | extend timestamp = AzureNetworkAnalytics_CL_TimeGenerated