ProofpointPOD - Multiple archived attachments to the same recipient

let lbtime = 30m;
let msgthreshold = 3;
let compressedTypes = dynamic(['zip', 'rar', 'tar', 'x-7z-compressed']);
ProofpointPOD
| where TimeGenerated > ago(lbtime)
| where EventType == 'message'
| where NetworkDirection == 'outbound'
| extend attachedMimeType = todynamic(MsgParts)[0]['detectedMime']
| where attachedMimeType has_any (compressedTypes)
| summarize count(), make_set(attachedMimeType) by SrcUserUpn, DstUserUpn
| where count_ > msgthreshold
| extend AccountCustomEntity = SrcUserUpn

name: ProofpointPOD - Multiple archived attachments to the same recipient
relevantTechniques:
- T1567
requiredDataConnectors:
- dataTypes:
  - ProofpointPOD_message_CL
  connectorId: ProofpointPOD
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Proofpoint On demand(POD) Email Security/Analytic Rules/ProofpointPODMultipleArchivedAttachmentsToSameRecipient.yaml
query: |
  let lbtime = 30m;
  let msgthreshold = 3;
  let compressedTypes = dynamic(['zip', 'rar', 'tar', 'x-7z-compressed']);
  ProofpointPOD
  | where TimeGenerated > ago(lbtime)
  | where EventType == 'message'
  | where NetworkDirection == 'outbound'
  | extend attachedMimeType = todynamic(MsgParts)[0]['detectedMime']
  | where attachedMimeType has_any (compressedTypes)
  | summarize count(), make_set(attachedMimeType) by SrcUserUpn, DstUserUpn
  | where count_ > msgthreshold
  | extend AccountCustomEntity = SrcUserUpn  
tactics:
- Exfiltration
description: |
    'Detects when multiple emails where sent to the same recipient with large archived attachments.'
entityMappings:
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: FullName
  entityType: Account
queryFrequency: 30m
triggerOperator: gt
version: 1.0.2
queryPeriod: 30m
status: Available
kind: Scheduled
severity: Medium
triggerThreshold: 0
id: bda5a2bd-979b-4828-a91f-27c2a5048f7f

{
  "$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/bda5a2bd-979b-4828-a91f-27c2a5048f7f')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/bda5a2bd-979b-4828-a91f-27c2a5048f7f')]",
      "properties": {
        "alertRuleTemplateName": "bda5a2bd-979b-4828-a91f-27c2a5048f7f",
        "customDetails": null,
        "description": "'Detects when multiple emails where sent to the same recipient with large archived attachments.'\n",
        "displayName": "ProofpointPOD - Multiple archived attachments to the same recipient",
        "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/ProofpointPODMultipleArchivedAttachmentsToSameRecipient.yaml",
        "query": "let lbtime = 30m;\nlet msgthreshold = 3;\nlet compressedTypes = dynamic(['zip', 'rar', 'tar', 'x-7z-compressed']);\nProofpointPOD\n| where TimeGenerated > ago(lbtime)\n| where EventType == 'message'\n| where NetworkDirection == 'outbound'\n| extend attachedMimeType = todynamic(MsgParts)[0]['detectedMime']\n| where attachedMimeType has_any (compressedTypes)\n| summarize count(), make_set(attachedMimeType) by SrcUserUpn, DstUserUpn\n| where count_ > msgthreshold\n| extend AccountCustomEntity = SrcUserUpn\n",
        "queryFrequency": "PT30M",
        "queryPeriod": "PT30M",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Exfiltration"
        ],
        "techniques": [
          "T1567"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}