TI map Email entity to CommonSecurityLog

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let emailregex = @'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$';
ThreatIntelligenceIndicator
| where TimeGenerated >= ago(ioc_lookBack) and ExpirationDateTime > now()
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where Active == true
//Filtering the table for Email related IOCs
| where isnotempty(EmailSenderAddress)
// 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 (
    CommonSecurityLog | where TimeGenerated >= ago(dt_lookBack) and isnotempty(DestinationUserID)
    // Filtering PAN Logs for specific event type to match relevant email entities
    | where DeviceVendor == "Palo Alto Networks" and  DeviceEventClassID == "wildfire" and ApplicationProtocol in ("smtp","pop3")
    | extend DestinationUserID = tolower(DestinationUserID)
    | where DestinationUserID matches regex emailregex
    | extend CommonSecurityLog_TimeGenerated = TimeGenerated
)
on $left.EmailSenderAddress == $right.DestinationUserID
| where CommonSecurityLog_TimeGenerated < ExpirationDateTime
| summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId, DestinationUserID
| project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore, EmailSenderName, EmailRecipient,
EmailSourceDomain, EmailSourceIpAddress, EmailSubject, FileHashValue, FileHashType, DestinationUserID, DeviceEventClassID, LogSeverity, DeviceAction, SourceIP, SourcePort,
DestinationIP, DestinationPort, Protocol, ApplicationProtocol
| extend timestamp = CommonSecurityLog_TimeGenerated, AccountCustomEntity = DestinationUserID, IPCustomEntity = SourceIP, URLCustomEntity = Url

version: 1.2.2
queryFrequency: 1h
requiredDataConnectors:
- connectorId: PaloAltoNetworks
  dataTypes:
  - CommonSecurityLog
- connectorId: ThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: ThreatIntelligenceTaxii
  dataTypes:
  - ThreatIntelligenceIndicator
entityMappings:
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: FullName
  entityType: Account
- fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
  entityType: IP
- fieldMappings:
  - columnName: URLCustomEntity
    identifier: Url
  entityType: URL
kind: Scheduled
queryPeriod: 14d
severity: Medium
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let emailregex = @'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$';
  ThreatIntelligenceIndicator
  | where TimeGenerated >= ago(ioc_lookBack) and ExpirationDateTime > now()
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true
  //Filtering the table for Email related IOCs
  | where isnotempty(EmailSenderAddress)
  // 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 (
      CommonSecurityLog | where TimeGenerated >= ago(dt_lookBack) and isnotempty(DestinationUserID)
      // Filtering PAN Logs for specific event type to match relevant email entities
      | where DeviceVendor == "Palo Alto Networks" and  DeviceEventClassID == "wildfire" and ApplicationProtocol in ("smtp","pop3")
      | extend DestinationUserID = tolower(DestinationUserID)
      | where DestinationUserID matches regex emailregex
      | extend CommonSecurityLog_TimeGenerated = TimeGenerated
  )
  on $left.EmailSenderAddress == $right.DestinationUserID
  | where CommonSecurityLog_TimeGenerated < ExpirationDateTime
  | summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId, DestinationUserID
  | project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore, EmailSenderName, EmailRecipient,
  EmailSourceDomain, EmailSourceIpAddress, EmailSubject, FileHashValue, FileHashType, DestinationUserID, DeviceEventClassID, LogSeverity, DeviceAction, SourceIP, SourcePort,
  DestinationIP, DestinationPort, Protocol, ApplicationProtocol
  | extend timestamp = CommonSecurityLog_TimeGenerated, AccountCustomEntity = DestinationUserID, IPCustomEntity = SourceIP, URLCustomEntity = Url  
triggerOperator: gt
id: ffcd575b-3d54-482a-a6d8-d0de13b6ac63
description: |
    'Identifies a match in CommonSecurityLog table from any Email IOC from TI'
triggerThreshold: 0
name: TI map Email entity to CommonSecurityLog
tactics:
- Impact
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/EmailEntity_PaloAlto.yaml

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/ffcd575b-3d54-482a-a6d8-d0de13b6ac63')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/ffcd575b-3d54-482a-a6d8-d0de13b6ac63')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01",
      "properties": {
        "displayName": "TI map Email entity to CommonSecurityLog",
        "description": "'Identifies a match in CommonSecurityLog table from any Email IOC from TI'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "let dt_lookBack = 1h;\nlet ioc_lookBack = 14d;\nlet emailregex = @'^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\\.[a-zA-Z0-9-.]+$';\nThreatIntelligenceIndicator\n| where TimeGenerated >= ago(ioc_lookBack) and ExpirationDateTime > now()\n| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId\n| where Active == true\n//Filtering the table for Email related IOCs\n| where isnotempty(EmailSenderAddress)\n// 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\n| join kind=innerunique (\n    CommonSecurityLog | where TimeGenerated >= ago(dt_lookBack) and isnotempty(DestinationUserID)\n    // Filtering PAN Logs for specific event type to match relevant email entities\n    | where DeviceVendor == \"Palo Alto Networks\" and  DeviceEventClassID == \"wildfire\" and ApplicationProtocol in (\"smtp\",\"pop3\")\n    | extend DestinationUserID = tolower(DestinationUserID)\n    | where DestinationUserID matches regex emailregex\n    | extend CommonSecurityLog_TimeGenerated = TimeGenerated\n)\non $left.EmailSenderAddress == $right.DestinationUserID\n| where CommonSecurityLog_TimeGenerated < ExpirationDateTime\n| summarize CommonSecurityLog_TimeGenerated = arg_max(CommonSecurityLog_TimeGenerated, *) by IndicatorId, DestinationUserID\n| project CommonSecurityLog_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, Url, ExpirationDateTime, ConfidenceScore, EmailSenderName, EmailRecipient,\nEmailSourceDomain, EmailSourceIpAddress, EmailSubject, FileHashValue, FileHashType, DestinationUserID, DeviceEventClassID, LogSeverity, DeviceAction, SourceIP, SourcePort,\nDestinationIP, DestinationPort, Protocol, ApplicationProtocol\n| extend timestamp = CommonSecurityLog_TimeGenerated, AccountCustomEntity = DestinationUserID, IPCustomEntity = SourceIP, URLCustomEntity = Url\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "alertRuleTemplateName": "ffcd575b-3d54-482a-a6d8-d0de13b6ac63",
        "customDetails": null,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "identifier": "FullName",
                "columnName": "AccountCustomEntity"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "identifier": "Address",
                "columnName": "IPCustomEntity"
              }
            ]
          },
          {
            "entityType": "URL",
            "fieldMappings": [
              {
                "identifier": "Url",
                "columnName": "URLCustomEntity"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/EmailEntity_PaloAlto.yaml",
        "templateVersion": "1.2.2"
      }
    }
  ]
}