ProofpointPOD - Suspicious attachment

let lbtime = 10m;
let disallowed_ext = dynamic(['ps1', 'exe', 'vbs', 'js', 'scr']);
ProofpointPOD
| where TimeGenerated > ago(lbtime)
| where EventType == 'message'
| where NetworkDirection == 'inbound'
| where FilterDisposition !in ('reject', 'discard')
| extend attachedExt = todynamic(MsgParts)[0]['detectedExt']
| where tolower(attachedExt) in (disallowed_ext)
| project SrcUserUpn, AccountCustomEntity = parse_json(DstUserUpn)[0], attachedExt

relevantTechniques:
- T1566
name: ProofpointPOD - Suspicious attachment
requiredDataConnectors:
- dataTypes:
  - ProofpointPOD_message_CL
  connectorId: ProofpointPOD
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: AccountCustomEntity
  entityType: Account
triggerThreshold: 0
id: f6a51e2c-2d6a-4f92-a090-cfb002ca611f
tactics:
- InitialAccess
version: 1.0.2
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Proofpoint On demand(POD) Email Security/Analytic Rules/ProofpointPODSuspiciousAttachment.yaml
queryPeriod: 10m
kind: Scheduled
queryFrequency: 10m
severity: Medium
status: Available
description: |
    'Detects when email contains suspicious attachment (file type).'
query: |
  let lbtime = 10m;
  let disallowed_ext = dynamic(['ps1', 'exe', 'vbs', 'js', 'scr']);
  ProofpointPOD
  | where TimeGenerated > ago(lbtime)
  | where EventType == 'message'
  | where NetworkDirection == 'inbound'
  | where FilterDisposition !in ('reject', 'discard')
  | extend attachedExt = todynamic(MsgParts)[0]['detectedExt']
  | where tolower(attachedExt) in (disallowed_ext)
  | project SrcUserUpn, AccountCustomEntity = parse_json(DstUserUpn)[0], attachedExt  
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/f6a51e2c-2d6a-4f92-a090-cfb002ca611f')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/f6a51e2c-2d6a-4f92-a090-cfb002ca611f')]",
      "properties": {
        "alertRuleTemplateName": "f6a51e2c-2d6a-4f92-a090-cfb002ca611f",
        "customDetails": null,
        "description": "'Detects when email contains suspicious attachment (file type).'\n",
        "displayName": "ProofpointPOD - Suspicious attachment",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "FullName"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Proofpoint On demand(POD) Email Security/Analytic Rules/ProofpointPODSuspiciousAttachment.yaml",
        "query": "let lbtime = 10m;\nlet disallowed_ext = dynamic(['ps1', 'exe', 'vbs', 'js', 'scr']);\nProofpointPOD\n| where TimeGenerated > ago(lbtime)\n| where EventType == 'message'\n| where NetworkDirection == 'inbound'\n| where FilterDisposition !in ('reject', 'discard')\n| extend attachedExt = todynamic(MsgParts)[0]['detectedExt']\n| where tolower(attachedExt) in (disallowed_ext)\n| project SrcUserUpn, AccountCustomEntity = parse_json(DstUserUpn)[0], attachedExt\n",
        "queryFrequency": "PT10M",
        "queryPeriod": "PT10M",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1566"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}