Cisco SEG - Unexpected link

let u_cat = dynamic(['Unclassified']);
CiscoSEGEvent
| where NetworkDirection =~ 'Incoming'
| where tostring(AdditionalFields) has 'ESAURLDetails'
| extend link_cat = extract(@"'Category': '(.*?)'", 1, tostring(AdditionalFields))
| where link_cat in~ (u_cat)
| extend AccountCustomEntity = DstUserName

kind: Scheduled
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CiscoSEG/Analytic Rules/CiscoSEGUnclassifiedLink.yaml
severity: Medium
name: Cisco SEG - Unexpected link
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: AccountCustomEntity
    identifier: Name
relevantTechniques:
- T1566
queryFrequency: 1h
triggerThreshold: 0
queryPeriod: 1h
description: |
    'Detects mails with suspicious links.'
id: 9cb4a02d-3708-42ba-b33b-0fdd360ce4b6
version: 1.0.1
tactics:
- InitialAccess
query: |
  let u_cat = dynamic(['Unclassified']);
  CiscoSEGEvent
  | where NetworkDirection =~ 'Incoming'
  | where tostring(AdditionalFields) has 'ESAURLDetails'
  | extend link_cat = extract(@"'Category': '(.*?)'", 1, tostring(AdditionalFields))
  | where link_cat in~ (u_cat)
  | extend AccountCustomEntity = DstUserName  
status: Available
requiredDataConnectors:
- dataTypes:
  - CiscoSEGEvent
  connectorId: CiscoSEG
- dataTypes:
  - CiscoSEGEvent
  connectorId: CiscoSEGAma
triggerOperator: gt

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/9cb4a02d-3708-42ba-b33b-0fdd360ce4b6')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/9cb4a02d-3708-42ba-b33b-0fdd360ce4b6')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01-preview",
      "properties": {
        "displayName": "Cisco SEG - Unexpected link",
        "description": "'Detects mails with suspicious links.'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "let u_cat = dynamic(['Unclassified']);\nCiscoSEGEvent\n| where NetworkDirection =~ 'Incoming'\n| where tostring(AdditionalFields) has 'ESAURLDetails'\n| extend link_cat = extract(@\"'Category': '(.*?)'\", 1, tostring(AdditionalFields))\n| where link_cat in~ (u_cat)\n| extend AccountCustomEntity = DstUserName\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1566"
        ],
        "alertRuleTemplateName": "9cb4a02d-3708-42ba-b33b-0fdd360ce4b6",
        "customDetails": null,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "identifier": "Name",
                "columnName": "AccountCustomEntity"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CiscoSEG/Analytic Rules/CiscoSEGUnclassifiedLink.yaml",
        "status": "Available",
        "templateVersion": "1.0.1"
      }
    }
  ]
}