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

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

ARM