TI Map IP entity to AzureNetworkAnalytics_CL (NSG Flow Logs)

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 = 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)
| 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 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 Id, ObservableValue
| where IsActive and (ValidUntil > now() or isempty(ValidUntil));
// Perform a join between IP indicators and AzureNetworkAnalytics_CL logs for NSG Flow information
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 (
      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 < ValidUntil
  // 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 Id, PIP
  // Select the desired output fields
| extend Description = tostring(parse_json(Data).description)
| extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
| project AzureNetworkAnalytics_CL_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence,
    TI_ipEntity, Computer, FlowDirection_s, FlowStatus_s, FlowType_s, SrcPublicIPs_s, DestPublicIPs_s, PublicIPs_s, L7Protocol_s, DestPort_d, NetworkSourceIP, 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