Digital Guardian - Bulk exfiltration to external domain

let threshold = 10;
let corp_domain = dynamic(['example.com']);
DigitalGuardianDLPEvent
| where NetworkApplicationProtocol =~ 'SMTP'
| where isnotempty(inspected_document)
| extend s_domain = extract(@'@(.*)', 1, SrcUserName)
| extend d_domain = extract(@'@(.*)', 1, DstUserName)
| where s_domain in~ (corp_domain)
| where d_domain !in (corp_domain)
| summarize f = dcount(inspected_document) by SrcUserName, DstUserName, bin(TimeGenerated, 30m)
| where  f >= threshold
| extend AccountCustomEntity = SrcUserName

id: 5f75a873-b524-4ba5-a3b8-2c20db517148
tactics:
- Exfiltration
queryPeriod: 1h
triggerThreshold: 0
name: Digital Guardian - Bulk exfiltration to external domain
query: |
  let threshold = 10;
  let corp_domain = dynamic(['example.com']);
  DigitalGuardianDLPEvent
  | where NetworkApplicationProtocol =~ 'SMTP'
  | where isnotempty(inspected_document)
  | extend s_domain = extract(@'@(.*)', 1, SrcUserName)
  | extend d_domain = extract(@'@(.*)', 1, DstUserName)
  | where s_domain in~ (corp_domain)
  | where d_domain !in (corp_domain)
  | summarize f = dcount(inspected_document) by SrcUserName, DstUserName, bin(TimeGenerated, 30m)
  | where  f >= threshold
  | extend AccountCustomEntity = SrcUserName  
severity: Medium
triggerOperator: gt
kind: Scheduled
relevantTechniques:
- T1048
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Digital Guardian Data Loss Prevention/Analytic Rules/DigitalGuardianFilesSentToExternalDomain.yaml
queryFrequency: 1h
requiredDataConnectors:
- connectorId: SyslogAma
  datatypes:
  - Syslog
description: |
    'Detects bulk exfiltration to external domain.'
status: Available
version: 1.0.2
entityMappings:
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: Name
  entityType: Account

{
  "$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/5f75a873-b524-4ba5-a3b8-2c20db517148')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/5f75a873-b524-4ba5-a3b8-2c20db517148')]",
      "properties": {
        "alertRuleTemplateName": "5f75a873-b524-4ba5-a3b8-2c20db517148",
        "customDetails": null,
        "description": "'Detects bulk exfiltration to external domain.'\n",
        "displayName": "Digital Guardian - Bulk exfiltration to external domain",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "Name"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Digital Guardian Data Loss Prevention/Analytic Rules/DigitalGuardianFilesSentToExternalDomain.yaml",
        "query": "let threshold = 10;\nlet corp_domain = dynamic(['example.com']);\nDigitalGuardianDLPEvent\n| where NetworkApplicationProtocol =~ 'SMTP'\n| where isnotempty(inspected_document)\n| extend s_domain = extract(@'@(.*)', 1, SrcUserName)\n| extend d_domain = extract(@'@(.*)', 1, DstUserName)\n| where s_domain in~ (corp_domain)\n| where d_domain !in (corp_domain)\n| summarize f = dcount(inspected_document) by SrcUserName, DstUserName, bin(TimeGenerated, 30m)\n| where  f >= threshold\n| extend AccountCustomEntity = SrcUserName\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Exfiltration"
        ],
        "techniques": [
          "T1048"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}