TI Map Email entity to Cloud App Events

Original query, unchanged.

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let emailregex = @'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$';
ThreatIntelIndicators
  | where TimeGenerated >= ago(ioc_lookBack)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
  | where IsActive and (ValidUntil > now() or isempty(ValidUntil))
//extract key part of kv pair
  | extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
  | where IndicatorType == "email-addr"
  | extend EmailSenderAddress = ObservableValue
  | extend EmailSourceDomain = substring(EmailSenderAddress, indexof(EmailSenderAddress, "@") + 1, strlen(EmailSenderAddress) - indexof(EmailSenderAddress, "@") - 1)
  | project-reorder *, EmailSenderAddress, EmailSourceDomain, Type
  | extend IndicatorId = tostring(split(Id, "--")[2])
  | join kind=innerunique (CloudAppEvents
| extend User_Id = tostring(RawEventData.UserId)
| where isnotempty(User_Id)
| where TimeGenerated >= ago(dt_lookBack) and isnotempty(Application)
| extend CloudAppEvents_TimeGenerated = TimeGenerated 
| where User_Id matches regex emailregex) on $left.EmailSenderAddress == $right.User_Id
| where CloudAppEvents_TimeGenerated < ValidUntil
| summarize CloudAppEvents_TimeGenerated = argmax(CloudAppEvents_TimeGenerated, *) by IndicatorId, User_Id
| extend Name = tostring(split(User_Id, '@', 0)[0]), UPNSuffix = tostring(split(User_Id, '@', 1)[0])
| extend timestamp = CloudAppEvents_TimeGenerated