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

id: 9e18b6c3-d172-4bc6-a7d9-cc7b0a03a69e
relevantTechniques:
- T1566
- T1071
- T1505
triggerOperator: gt
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cyfirma Attack Surface/Analytic Rules/ASOpenPortsMediumRule.yaml
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
requiredDataConnectors:
- dataTypes:
  - CyfirmaASOpenPortsAlerts_CL
  connectorId: CyfirmaAttackSurfaceAlertsConnector
queryFrequency: 5m
eventGroupingSettings:
  aggregationKind: AlertPerResult
queryPeriod: 5m
status: Available
incidentConfiguration:
  groupingConfiguration:
    enabled: false
    reopenClosedIncident: false
    matchingMethod: AllEntities
    lookbackDuration: PT5H
  createIncident: true
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  
name: CYFIRMA - Attack Surface - Open Ports Medium Rule
kind: Scheduled
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
triggerThreshold: 0
version: 1.0.1
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}}
customDetails:
  TimeGenerated: TimeGenerated
  OpenPorts: OpenPorts
  LastSeen: LastSeen
  RiskScore: RiskScore
  FirstSeen: FirstSeen
  AlertUID: AlertUID
  WebServerVersion: WebServerVersion
  Description: Description
  UID: UID
  WebServer: WebServer

ARM