TI Map IP Entity to SigninLogs

Original query, unchanged.

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let Signins = materialize(union isfuzzy=true
  (SigninLogs
  | where TimeGenerated >= ago(dt_lookBack)),
  (AADNonInteractiveUserSignInLogs
  | where TimeGenerated >= ago(dt_lookBack)
  | extend Status = todynamic(Status), LocationDetails = todynamic(LocationDetails)));
let SigninIPs = Signins | summarize make_list(IPAddress);
let TI = materialize(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 = NetworkSourceIP
  | extend Url = iff(ObservableKey == "url:value", ObservableValue, "")
  | where TI_ipEntity in (SigninIPs)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
  | extend Description = tostring(parse_json(Data).description)
  | where IsActive and (ValidUntil > now() or isempty(ValidUntil))
  | where Description !contains_cs "State: inactive;" and Description !contains_cs "State: falsepos;");
TI
   | 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 (Signins) on $left.TI_ipEntity == $right.IPAddress
| project-rename SigninLogs_TimeGenerated = TimeGenerated
| where SigninLogs_TimeGenerated < ValidUntil
| extend StatusCode = tostring(Status.errorCode), StatusDetails = tostring(Status.additionalDetails), StatusReason = tostring(Status.failureReason)
| summarize SigninLogs_TimeGenerated = arg_max(SigninLogs_TimeGenerated, *) by Id, IPAddress
| extend Description = tostring(parse_json(Data).description)
| extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
| project SigninLogs_TimeGenerated, Description, ActivityGroupNames, Id, ValidUntil, Confidence, TI_ipEntity, IPAddress, UserPrincipalName, AppDisplayName, StatusCode, StatusDetails, StatusReason, NetworkSourceIP, Type, Url
| extend timestamp = SigninLogs_TimeGenerated, Name = tostring(split(UserPrincipalName, '@', 0)[0]), UPNSuffix = tostring(split(UserPrincipalName, '@', 1)[0])