CYFIRMA - Attack Surface - Open Ports High Rule | Microsoft Sentinel Analytic Rules

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Id	87e7eb3f-bb8e-46e5-8807-d3fc63d0f676
Rulename	CYFIRMA - Attack Surface - Open Ports High Rule
Description	“This rule is triggered when CYFIRMA identifies open and publicly accessible ports on internet-facing assets. Exposed services may include SSH, RDP, HTTP, or other potentially sensitive ports, increasing the risk of unauthorized access, exploitation, or reconnaissance by threat actors. Monitoring open ports is critical to reducing the external attack surface and preventing misuse through brute force, service vulnerabilities, or protocol exploitation.”
Severity	High
Tactics	InitialAccess CommandAndControl Discovery DefenseEvasion Persistence
Techniques	T1566 T1071 T1505
Required data connectors	CyfirmaAttackSurfaceAlertsConnector
Kind	Scheduled
Query frequency	5m
Query period	5m
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cyfirma%20Attack%20Surface/Analytic%20Rules/ASOpenPortsHighRule.yaml
Version	1.0.1
Arm template	87e7eb3f-bb8e-46e5-8807-d3fc63d0f676.json

KQL

// High Severity - Open Ports Exposure Detected
let timeFrame = 5m;
CyfirmaASOpenPortsAlerts_CL
| where severity == 'Critical' and TimeGenerated between (ago(timeFrame) .. now())
| extend Description=description, FirstSeen=first_seen, LastSeen=last_seen, RiskScore=risk_score, Domain=sub_domain, TopDomain=top_domain, NetworkIP=ip, AlertUID=alert_uid, UID=uid, WebServer=web_server, WebServerVersion=web_server_version, OpenPorts=open_ports, ProviderName="CYFIRMA", ProductName="DeCYFIR/DeTCT"
| project
    TimeGenerated,
    Description,
    Domain,
    TopDomain,
    RiskScore,
    FirstSeen,
    LastSeen,
    NetworkIP,
    AlertUID,
    UID,
    WebServer,
    WebServerVersion,
    OpenPorts,
    ProductName,
    ProviderName

YAML

tactics:
- InitialAccess
- CommandAndControl
- Discovery
- DefenseEvasion
- Persistence
description: |
  "This rule is triggered when CYFIRMA identifies open and publicly accessible ports on internet-facing assets. Exposed services may include SSH, RDP, HTTP, or other potentially sensitive ports, increasing the risk of unauthorized access, exploitation, or reconnaissance by threat actors. Monitoring open ports is critical to reducing the external attack surface and preventing misuse through brute force, service vulnerabilities, or protocol exploitation."
incidentConfiguration:
  createIncident: true
  groupingConfiguration:
    reopenClosedIncident: false
    lookbackDuration: PT5H
    enabled: false
    matchingMethod: AllEntities
queryPeriod: 5m
severity: High
customDetails:
  Description: Description
  WebServerVersion: WebServerVersion
  WebServer: WebServer
  UID: UID
  TimeGenerated: TimeGenerated
  FirstSeen: FirstSeen
  AlertUID: AlertUID
  RiskScore: RiskScore
  OpenPorts: OpenPorts
  LastSeen: LastSeen
queryFrequency: 5m
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cyfirma%20Attack%20Surface/Analytic%20Rules/ASOpenPortsHighRule.yaml
kind: Scheduled
id: 87e7eb3f-bb8e-46e5-8807-d3fc63d0f676
triggerOperator: gt
alertDetailsOverride:
  alertDynamicProperties:
  - alertProperty: ProductName
    value: ProductName
  - alertProperty: ProviderName
    value: ProviderName
  alertDescriptionFormat: CYFIRMA - High Severity Open Ports Exposure Detected on Assets - {{Description}}
  alertDisplayNameFormat: 'CYFIRMA - High Severity Open Ports Exposure Detected on Assets - Domain: {{Domain}}, IP: {{NetworkIP}}'
status: Available
relevantTechniques:
- T1566
- T1071
- T1505
triggerThreshold: 0
eventGroupingSettings:
  aggregationKind: AlertPerResult
requiredDataConnectors:
- dataTypes:
  - CyfirmaASOpenPortsAlerts_CL
  connectorId: CyfirmaAttackSurfaceAlertsConnector
version: 1.0.1
name: CYFIRMA - Attack Surface - Open Ports High Rule
entityMappings:
- entityType: DNS
  fieldMappings:
  - columnName: Domain
    identifier: DomainName
- entityType: Host
  fieldMappings:
  - columnName: TopDomain
    identifier: HostName
  - columnName: Domain
    identifier: DnsDomain
- entityType: IP
  fieldMappings:
  - columnName: NetworkIP
    identifier: Address
query: |
  // High Severity - Open Ports Exposure Detected
  let timeFrame = 5m;
  CyfirmaASOpenPortsAlerts_CL
  | where severity == 'Critical' and TimeGenerated between (ago(timeFrame) .. now())
  | extend Description=description, FirstSeen=first_seen, LastSeen=last_seen, RiskScore=risk_score, Domain=sub_domain, TopDomain=top_domain, NetworkIP=ip, AlertUID=alert_uid, UID=uid, WebServer=web_server, WebServerVersion=web_server_version, OpenPorts=open_ports, ProviderName="CYFIRMA", ProductName="DeCYFIR/DeTCT"
  | project
      TimeGenerated,
      Description,
      Domain,
      TopDomain,
      RiskScore,
      FirstSeen,
      LastSeen,
      NetworkIP,
      AlertUID,
      UID,
      WebServer,
      WebServerVersion,
      OpenPorts,
      ProductName,
      ProviderName

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/87e7eb3f-bb8e-46e5-8807-d3fc63d0f676')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/87e7eb3f-bb8e-46e5-8807-d3fc63d0f676')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "CYFIRMA - High Severity Open Ports Exposure Detected on Assets - {{Description}}",
          "alertDisplayNameFormat": "CYFIRMA - High Severity Open Ports Exposure Detected on Assets - Domain: {{Domain}}, IP: {{NetworkIP}}",
          "alertDynamicProperties": [
            {
              "alertProperty": "ProductName",
              "value": "ProductName"
            },
            {
              "alertProperty": "ProviderName",
              "value": "ProviderName"
            }
          ]
        },
        "alertRuleTemplateName": "87e7eb3f-bb8e-46e5-8807-d3fc63d0f676",
        "customDetails": {
          "AlertUID": "AlertUID",
          "Description": "Description",
          "FirstSeen": "FirstSeen",
          "LastSeen": "LastSeen",
          "OpenPorts": "OpenPorts",
          "RiskScore": "RiskScore",
          "TimeGenerated": "TimeGenerated",
          "UID": "UID",
          "WebServer": "WebServer",
          "WebServerVersion": "WebServerVersion"
        },
        "description": "\"This rule is triggered when CYFIRMA identifies open and publicly accessible ports on internet-facing assets. Exposed services may include SSH, RDP, HTTP, or other potentially sensitive ports, increasing the risk of unauthorized access, exploitation, or reconnaissance by threat actors. Monitoring open ports is critical to reducing the external attack surface and preventing misuse through brute force, service vulnerabilities, or protocol exploitation.\"\n",
        "displayName": "CYFIRMA - Attack Surface - Open Ports High Rule",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "DNS",
            "fieldMappings": [
              {
                "columnName": "Domain",
                "identifier": "DomainName"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "TopDomain",
                "identifier": "HostName"
              },
              {
                "columnName": "Domain",
                "identifier": "DnsDomain"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "NetworkIP",
                "identifier": "Address"
              }
            ]
          }
        ],
        "eventGroupingSettings": {
          "aggregationKind": "AlertPerResult"
        },
        "incidentConfiguration": {
          "createIncident": true,
          "groupingConfiguration": {
            "enabled": false,
            "lookbackDuration": "PT5H",
            "matchingMethod": "AllEntities",
            "reopenClosedIncident": false
          }
        },
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cyfirma%20Attack%20Surface/Analytic%20Rules/ASOpenPortsHighRule.yaml",
        "query": "// High Severity - Open Ports Exposure Detected\nlet timeFrame = 5m;\nCyfirmaASOpenPortsAlerts_CL\n| where severity == 'Critical' and TimeGenerated between (ago(timeFrame) .. now())\n| extend Description=description, FirstSeen=first_seen, LastSeen=last_seen, RiskScore=risk_score, Domain=sub_domain, TopDomain=top_domain, NetworkIP=ip, AlertUID=alert_uid, UID=uid, WebServer=web_server, WebServerVersion=web_server_version, OpenPorts=open_ports, ProviderName=\"CYFIRMA\", ProductName=\"DeCYFIR/DeTCT\"\n| project\n    TimeGenerated,\n    Description,\n    Domain,\n    TopDomain,\n    RiskScore,\n    FirstSeen,\n    LastSeen,\n    NetworkIP,\n    AlertUID,\n    UID,\n    WebServer,\n    WebServerVersion,\n    OpenPorts,\n    ProductName,\n    ProviderName\n",
        "queryFrequency": "PT5M",
        "queryPeriod": "PT5M",
        "severity": "High",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl",
          "DefenseEvasion",
          "Discovery",
          "InitialAccess",
          "Persistence"
        ],
        "techniques": [
          "T1071",
          "T1505",
          "T1566"
        ],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}