TI map Email entity to EmailEvents

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let EmailEvents_ = materialize(EmailEvents | where isnotempty(RecipientEmailAddress) and isnotempty(SenderFromAddress) and TimeGenerated >= ago(dt_lookBack) and DeliveryAction !has "Blocked" | project-rename  EmailEvents_TimeGenerated = TimeGenerated | extend SenderFromAddress = tolower(SenderFromAddress) | extend RecipientEmailAddress = tolower(RecipientEmailAddress));
let SenderAddresses = EmailEvents_ | distinct  SenderFromAddress | summarize make_list(SenderFromAddress);
let RecipientAddresses = EmailEvents_ | distinct  RecipientEmailAddress | summarize make_list(RecipientEmailAddress);
let TI = materialize(ThreatIntelligenceIndicator
| where TimeGenerated >= ago(ioc_lookBack)
| where isnotempty(EmailSenderAddress)
| extend TI_EmailAddress = tolower(EmailSenderAddress)
| where TI_EmailAddress in (SenderAddresses) or TI_EmailAddress in (RecipientAddresses)
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where Active == true and ExpirationDateTime > now());
(union
  (TI | join kind=innerunique (EmailEvents_) on $left.TI_EmailAddress == $right.SenderFromAddress),
  (TI | join kind=innerunique (EmailEvents_) on $left.TI_EmailAddress == $right.RecipientEmailAddress))
| where EmailEvents_TimeGenerated < ExpirationDateTime
| summarize EmailEvents_TimeGenerated = arg_max(EmailEvents_TimeGenerated, *) by IndicatorId, TI_EmailAddress
| project EmailEvents_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DomainName, RecipientEmailAddress, SenderFromAddress, Subject, ConfidenceLevel, Url, Type, TI_EmailAddress, TrafficLightProtocolLevel, DeliveryAction, DeliveryLocation, EmailDirection
| extend Name = tostring(split(RecipientEmailAddress, '@', 0)[0]), UPNSuffix = tostring(split(RecipientEmailAddress, '@', 1)[0])
| extend timestamp = EmailEvents_TimeGenerated

relevantTechniques:
- T1566
name: TI map Email entity to EmailEvents
requiredDataConnectors:
- dataTypes:
  - EmailEvents
  connectorId: Office365
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligence
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligenceTaxii
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: MicrosoftDefenderThreatIntelligence
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: RecipientEmailAddress
  - identifier: Name
    columnName: Name
  - identifier: UPNSuffix
    columnName: UPNSuffix
  entityType: Account
triggerThreshold: 0
id: 11f7c6e3-f066-4b3c-9a81-b487ec0a6873
tactics:
- InitialAccess
version: 1.0.2
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/EmailEntity_EmailEvents.yaml
queryPeriod: 14d
kind: Scheduled
queryFrequency: 1h
severity: Medium
description: |
    'Identifies a match in EmailEvents table from any Email IOC from TI'
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let EmailEvents_ = materialize(EmailEvents | where isnotempty(RecipientEmailAddress) and isnotempty(SenderFromAddress) and TimeGenerated >= ago(dt_lookBack) and DeliveryAction !has "Blocked" | project-rename  EmailEvents_TimeGenerated = TimeGenerated | extend SenderFromAddress = tolower(SenderFromAddress) | extend RecipientEmailAddress = tolower(RecipientEmailAddress));
  let SenderAddresses = EmailEvents_ | distinct  SenderFromAddress | summarize make_list(SenderFromAddress);
  let RecipientAddresses = EmailEvents_ | distinct  RecipientEmailAddress | summarize make_list(RecipientEmailAddress);
  let TI = materialize(ThreatIntelligenceIndicator
  | where TimeGenerated >= ago(ioc_lookBack)
  | where isnotempty(EmailSenderAddress)
  | extend TI_EmailAddress = tolower(EmailSenderAddress)
  | where TI_EmailAddress in (SenderAddresses) or TI_EmailAddress in (RecipientAddresses)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true and ExpirationDateTime > now());
  (union
    (TI | join kind=innerunique (EmailEvents_) on $left.TI_EmailAddress == $right.SenderFromAddress),
    (TI | join kind=innerunique (EmailEvents_) on $left.TI_EmailAddress == $right.RecipientEmailAddress))
  | where EmailEvents_TimeGenerated < ExpirationDateTime
  | summarize EmailEvents_TimeGenerated = arg_max(EmailEvents_TimeGenerated, *) by IndicatorId, TI_EmailAddress
  | project EmailEvents_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DomainName, RecipientEmailAddress, SenderFromAddress, Subject, ConfidenceLevel, Url, Type, TI_EmailAddress, TrafficLightProtocolLevel, DeliveryAction, DeliveryLocation, EmailDirection
  | extend Name = tostring(split(RecipientEmailAddress, '@', 0)[0]), UPNSuffix = tostring(split(RecipientEmailAddress, '@', 1)[0])
  | extend timestamp = EmailEvents_TimeGenerated  
triggerOperator: gt

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/11f7c6e3-f066-4b3c-9a81-b487ec0a6873')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/11f7c6e3-f066-4b3c-9a81-b487ec0a6873')]",
      "properties": {
        "alertRuleTemplateName": "11f7c6e3-f066-4b3c-9a81-b487ec0a6873",
        "customDetails": null,
        "description": "'Identifies a match in EmailEvents table from any Email IOC from TI'\n",
        "displayName": "TI map Email entity to EmailEvents",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "RecipientEmailAddress",
                "identifier": "FullName"
              },
              {
                "columnName": "Name",
                "identifier": "Name"
              },
              {
                "columnName": "UPNSuffix",
                "identifier": "UPNSuffix"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/EmailEntity_EmailEvents.yaml",
        "query": "let dt_lookBack = 1h;\nlet ioc_lookBack = 14d;\nlet EmailEvents_ = materialize(EmailEvents | where isnotempty(RecipientEmailAddress) and isnotempty(SenderFromAddress) and TimeGenerated >= ago(dt_lookBack) and DeliveryAction !has \"Blocked\" | project-rename  EmailEvents_TimeGenerated = TimeGenerated | extend SenderFromAddress = tolower(SenderFromAddress) | extend RecipientEmailAddress = tolower(RecipientEmailAddress));\nlet SenderAddresses = EmailEvents_ | distinct  SenderFromAddress | summarize make_list(SenderFromAddress);\nlet RecipientAddresses = EmailEvents_ | distinct  RecipientEmailAddress | summarize make_list(RecipientEmailAddress);\nlet TI = materialize(ThreatIntelligenceIndicator\n| where TimeGenerated >= ago(ioc_lookBack)\n| where isnotempty(EmailSenderAddress)\n| extend TI_EmailAddress = tolower(EmailSenderAddress)\n| where TI_EmailAddress in (SenderAddresses) or TI_EmailAddress in (RecipientAddresses)\n| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId\n| where Active == true and ExpirationDateTime > now());\n(union\n  (TI | join kind=innerunique (EmailEvents_) on $left.TI_EmailAddress == $right.SenderFromAddress),\n  (TI | join kind=innerunique (EmailEvents_) on $left.TI_EmailAddress == $right.RecipientEmailAddress))\n| where EmailEvents_TimeGenerated < ExpirationDateTime\n| summarize EmailEvents_TimeGenerated = arg_max(EmailEvents_TimeGenerated, *) by IndicatorId, TI_EmailAddress\n| project EmailEvents_TimeGenerated, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, DomainName, RecipientEmailAddress, SenderFromAddress, Subject, ConfidenceLevel, Url, Type, TI_EmailAddress, TrafficLightProtocolLevel, DeliveryAction, DeliveryLocation, EmailDirection\n| extend Name = tostring(split(RecipientEmailAddress, '@', 0)[0]), UPNSuffix = tostring(split(RecipientEmailAddress, '@', 1)[0])\n| extend timestamp = EmailEvents_TimeGenerated\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1566"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}