Mimecast Secure Email Gateway - URL Protect

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Id	ea19dae6-bbb3-4444-a1b8-8e9ae6064aab
Rulename	Mimecast Secure Email Gateway - URL Protect
Description	Detect threat when potentially malicious url found
Severity	High
Tactics	InitialAccess Discovery Execution
Techniques	T1566
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_Url_Protect.yaml
Version	1.0.0
Arm template	ea19dae6-bbb3-4444-a1b8-8e9ae6064aab.json

KQL

MimecastSIEM_CL| where mimecastEventId_s=="mail_ttp_url" and reason_s != "clean"

YAML

requiredDataConnectors:
- connectorId: MimecastSIEMAPI
  dataTypes:
  - MimecastSIEM_CL
suppressionEnabled: false
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/MimecastSEG/Analytic Rules/MimecastSIEM_Url_Protect.yaml
triggerOperator: gt
incidentConfiguration:
  groupingConfiguration:
    matchingMethod: AllEntities
    enabled: true
    reopenClosedIncident: false
    lookbackDuration: 1d
  createIncident: true
severity: High
description: Detect threat when potentially malicious url found
relevantTechniques:
- T1566
eventGroupingSettings:
  aggregationKind: SingleAlert
suppressionDuration: 5h
triggerThreshold: 0
kind: Scheduled
query: MimecastSIEM_CL| where mimecastEventId_s=="mail_ttp_url" and reason_s != "clean"
name: Mimecast Secure Email Gateway - URL Protect
enabled: true
version: 1.0.0
queryFrequency: 5m
entityMappings:
- fieldMappings:
  - identifier: Sender
    columnName: sender_s
  - identifier: Recipient
    columnName: recipient_s
  - identifier: Subject
    columnName: subject_s
  entityType: MailMessage
customDetails:
  urlCategory: urlCategory_s
  senderDomain: senderDomain_s
  reason: reason_s
  SourceIP: SourceIP
  msgid: msgid_s
  credentialTheft: credentialTheft_s
  url: url_s
  route: route_s
  action: action_s
id: ea19dae6-bbb3-4444-a1b8-8e9ae6064aab
tactics:
- InitialAccess
- Discovery
- Execution
queryPeriod: 15m

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/ea19dae6-bbb3-4444-a1b8-8e9ae6064aab')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/ea19dae6-bbb3-4444-a1b8-8e9ae6064aab')]",
      "properties": {
        "alertRuleTemplateName": "ea19dae6-bbb3-4444-a1b8-8e9ae6064aab",
        "customDetails": {
          "action": "action_s",
          "credentialTheft": "credentialTheft_s",
          "msgid": "msgid_s",
          "reason": "reason_s",
          "route": "route_s",
          "senderDomain": "senderDomain_s",
          "SourceIP": "SourceIP",
          "url": "url_s",
          "urlCategory": "urlCategory_s"
        },
        "description": "Detect threat when potentially malicious url found",
        "displayName": "Mimecast Secure Email Gateway - URL Protect",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "MailMessage",
            "fieldMappings": [
              {
                "columnName": "sender_s",
                "identifier": "Sender"
              },
              {
                "columnName": "recipient_s",
                "identifier": "Recipient"
              },
              {
                "columnName": "subject_s",
                "identifier": "Subject"
              }
            ]
          }
        ],
        "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_Url_Protect.yaml",
        "query": "MimecastSIEM_CL| where mimecastEventId_s==\"mail_ttp_url\" and reason_s != \"clean\"",
        "queryFrequency": "PT5M",
        "queryPeriod": "PT15M",
        "severity": "High",
        "suppressionDuration": "PT5H",
        "suppressionEnabled": false,
        "tactics": [
          "Discovery",
          "Execution",
          "InitialAccess"
        ],
        "techniques": [
          "T1566"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}