Mimecast Secure Email Gateway - Attachment Protect

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Id	72264f4f-61fb-4f4f-96c4-635571a376c2
Rulename	Mimecast Secure Email Gateway - Attachment Protect
Description	Detect threat for mail attachment under the targeted threat protection
Severity	High
Tactics	Collection Exfiltration Discovery InitialAccess Execution
Techniques	T1114 T1566 T0865
Required data connectors	MimecastSIEMAPI
Kind	Scheduled
Query frequency	5m
Query period	15m
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/MimecastSEG/Analytic Rules/MimecastSIEM_Attachment.yaml
Version	1.0.0
Arm template	72264f4f-61fb-4f4f-96c4-635571a376c2.json

KQL

MimecastSIEM_CL| where mimecastEventId_s=="mail_ttp_attachment"

YAML

incidentConfiguration:
  createIncident: true
  groupingConfiguration:
    lookbackDuration: 1d
    reopenClosedIncident: false
    enabled: true
    matchingMethod: AllEntities
id: 72264f4f-61fb-4f4f-96c4-635571a376c2
enabled: true
queryPeriod: 15m
eventGroupingSettings:
  aggregationKind: SingleAlert
triggerThreshold: 0
name: Mimecast Secure Email Gateway - Attachment Protect
query: MimecastSIEM_CL| where mimecastEventId_s=="mail_ttp_attachment"
severity: High
relevantTechniques:
- T1114
- T1566
- T0865
triggerOperator: gt
kind: Scheduled
suppressionDuration: 5h
tactics:
- Collection
- Exfiltration
- Discovery
- InitialAccess
- Execution
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/MimecastSEG/Analytic Rules/MimecastSIEM_Attachment.yaml
customDetails:
  fileName: fileName_s
  sha256: sha256_s
  MsgId: MsgId_s
queryFrequency: 5m
requiredDataConnectors:
- connectorId: MimecastSIEMAPI
  dataTypes:
  - MimecastSIEM_CL
description: Detect threat for mail attachment under the targeted threat protection
suppressionEnabled: false
version: 1.0.0
entityMappings:
- fieldMappings:
  - columnName: Sender_s
    identifier: Sender
  - columnName: Recipient_s
    identifier: Recipient
  - columnName: Subject_s
    identifier: Subject
  entityType: MailMessage
- fieldMappings:
  - columnName: IP_s
    identifier: Address
  entityType: IP

ARM

{
  "$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/72264f4f-61fb-4f4f-96c4-635571a376c2')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/72264f4f-61fb-4f4f-96c4-635571a376c2')]",
      "properties": {
        "alertRuleTemplateName": "72264f4f-61fb-4f4f-96c4-635571a376c2",
        "customDetails": {
          "fileName": "fileName_s",
          "MsgId": "MsgId_s",
          "sha256": "sha256_s"
        },
        "description": "Detect threat for mail attachment under the targeted threat protection",
        "displayName": "Mimecast Secure Email Gateway - Attachment Protect",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "MailMessage",
            "fieldMappings": [
              {
                "columnName": "Sender_s",
                "identifier": "Sender"
              },
              {
                "columnName": "Recipient_s",
                "identifier": "Recipient"
              },
              {
                "columnName": "Subject_s",
                "identifier": "Subject"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IP_s",
                "identifier": "Address"
              }
            ]
          }
        ],
        "eventGroupingSettings": {
          "aggregationKind": "SingleAlert"
        },
        "incidentConfiguration": {
          "createIncident": true,
          "groupingConfiguration": {
            "enabled": true,
            "lookbackDuration": "P1D",
            "matchingMethod": "AllEntities",
            "reopenClosedIncident": false
          }
        },
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/MimecastSEG/Analytic Rules/MimecastSIEM_Attachment.yaml",
        "query": "MimecastSIEM_CL| where mimecastEventId_s==\"mail_ttp_attachment\"",
        "queryFrequency": "PT5M",
        "queryPeriod": "PT15M",
        "severity": "High",
        "subTechniques": [],
        "suppressionDuration": "PT5H",
        "suppressionEnabled": false,
        "tactics": [
          "Collection",
          "Discovery",
          "Execution",
          "Exfiltration",
          "InitialAccess"
        ],
        "techniques": [
          "T1114",
          "T1566"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}