CYFIRMA - Attack Surface - Open Ports Medium Rule

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Id	9e18b6c3-d172-4bc6-a7d9-cc7b0a03a69e
Rulename	CYFIRMA - Attack Surface - Open Ports Medium 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	Medium
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 Attack Surface/Analytic Rules/ASOpenPortsMediumRule.yaml
Version	1.0.1
Arm template	9e18b6c3-d172-4bc6-a7d9-cc7b0a03a69e.json

KQL

// Medium Severity - Open Ports Exposure Detected
let timeFrame = 5m;
CyfirmaASOpenPortsAlerts_CL
| where severity == 'High' 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

name: CYFIRMA - Attack Surface - Open Ports Medium Rule
eventGroupingSettings:
  aggregationKind: AlertPerResult
alertDetailsOverride:
  alertDynamicProperties:
  - alertProperty: ProductName
    value: DeCYFIR/DeTCT
  - alertProperty: ProviderName
    value: CYFIRMA
  alertDisplayNameFormat: 'CYFIRMA - Medium Severity Open Ports Exposure Detected on Assets - Domain: {{Domain}}, IP: {{NetworkIP}}'
  alertDescriptionFormat: CYFIRMA - Medium Severity Open Ports Exposure Detected on Assets - {{Description}}
id: 9e18b6c3-d172-4bc6-a7d9-cc7b0a03a69e
requiredDataConnectors:
- connectorId: CyfirmaAttackSurfaceAlertsConnector
  dataTypes:
  - CyfirmaASOpenPortsAlerts_CL
severity: Medium
triggerThreshold: 0
version: 1.0.1
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."
relevantTechniques:
- T1566
- T1071
- T1505
kind: Scheduled
queryPeriod: 5m
incidentConfiguration:
  createIncident: true
  groupingConfiguration:
    enabled: false
    reopenClosedIncident: false
    matchingMethod: AllEntities
    lookbackDuration: PT5H
tactics:
- InitialAccess
- CommandAndControl
- Discovery
- DefenseEvasion
- Persistence
customDetails:
  OpenPorts: OpenPorts
  WebServer: WebServer
  Description: Description
  AlertUID: AlertUID
  RiskScore: RiskScore
  TimeGenerated: TimeGenerated
  FirstSeen: FirstSeen
  WebServerVersion: WebServerVersion
  LastSeen: LastSeen
  UID: UID
queryFrequency: 5m
entityMappings:
- fieldMappings:
  - identifier: DomainName
    columnName: Domain
  entityType: DNS
- fieldMappings:
  - identifier: HostName
    columnName: TopDomain
  - identifier: DnsDomain
    columnName: Domain
  entityType: Host
- fieldMappings:
  - identifier: Address
    columnName: NetworkIP
  entityType: IP
status: Available
triggerOperator: gt
query: |
  // Medium Severity - Open Ports Exposure Detected
  let timeFrame = 5m;
  CyfirmaASOpenPortsAlerts_CL
  | where severity == 'High' 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  
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cyfirma Attack Surface/Analytic Rules/ASOpenPortsMediumRule.yaml

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/9e18b6c3-d172-4bc6-a7d9-cc7b0a03a69e')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/9e18b6c3-d172-4bc6-a7d9-cc7b0a03a69e')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "CYFIRMA - Medium Severity Open Ports Exposure Detected on Assets - {{Description}}",
          "alertDisplayNameFormat": "CYFIRMA - Medium Severity Open Ports Exposure Detected on Assets - Domain: {{Domain}}, IP: {{NetworkIP}}",
          "alertDynamicProperties": [
            {
              "alertProperty": "ProductName",
              "value": "DeCYFIR/DeTCT"
            },
            {
              "alertProperty": "ProviderName",
              "value": "CYFIRMA"
            }
          ]
        },
        "alertRuleTemplateName": "9e18b6c3-d172-4bc6-a7d9-cc7b0a03a69e",
        "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 Medium 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 Attack Surface/Analytic Rules/ASOpenPortsMediumRule.yaml",
        "query": "// Medium Severity - Open Ports Exposure Detected\nlet timeFrame = 5m;\nCyfirmaASOpenPortsAlerts_CL\n| where severity == 'High' and TimeGenerated between (ago(timeFrame) .. now())\n| extend \n    Description=description, \n    FirstSeen=first_seen, \n    LastSeen=last_seen, \n    RiskScore=risk_score, \n    Domain=sub_domain, \n    TopDomain=top_domain, \n    NetworkIP=ip, \n    AlertUID=alert_uid, \n    UID=uid, \n    WebServer=web_server, \n    WebServerVersion=web_server_version, \n    OpenPorts=open_ports, \n    ProviderName='CYFIRMA', \n    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": "Medium",
        "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"
    }
  ]
}