TI Map IP Entity to AzureActivity

Original query, unchanged.

let dt_lookBack = 1h; // Look back 1 hour for AzureActivity 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 AzureActivity logs to identify potential malicious activity
IP_Indicators
   | project-reorder *, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, TI_ipEntity
// using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated
| join kind=innerunique (
    AzureActivity | where TimeGenerated >= ago(dt_lookBack)
    // renaming time column so it is clear the log this came from
    | extend AzureActivity_TimeGenerated = TimeGenerated
)
on $left.TI_ipEntity == $right.CallerIpAddress
| where AzureActivity_TimeGenerated < ValidUntil
| summarize AzureActivity_TimeGenerated = arg_max(AzureActivity_TimeGenerated, *) by Id, CallerIpAddress
| extend Description = tostring(parse_json(Data).description)
| extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
| project AzureActivity_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence, TI_ipEntity, CallerIpAddress, 
Caller, OperationNameValue, ActivityStatusValue, CategoryValue, ResourceId, NetworkSourceIP, Type, Url
| extend timestamp = AzureActivity_TimeGenerated
| extend Name = iif(Caller has '@', tostring(split(Caller,'@',0)[0]), "")
| extend UPNSuffix = iif(Caller has '@', tostring(split(Caller,'@',1)[0]), "")
| extend AadUserId = iif(Caller !has '@', tostring(Caller), "")