CYFIRMA - Attack Surface - Cloud Weakness Medium Rule

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Id	b8a3c5e2-04d5-4b61-9b62-b4f53a417f74
Rulename	CYFIRMA - Attack Surface - Cloud Weakness Medium Rule
Description	“This rule detects cloud storage buckets (e.g., AWS S3) that are publicly accessible without authentication. Such misconfigurations can lead to data exfiltration, compliance violations, and reputational damage. The detection is based on Cyfirma’s Attack Surface Intelligence.”
Severity	Medium
Tactics	InitialAccess Collection Discovery Exfiltration
Techniques	T1087 T1087.004
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/ASCloudWeaknessMediumRule.yaml
Version	1.0.1
Arm template	b8a3c5e2-04d5-4b61-9b62-b4f53a417f74.json

KQL

// Medium Severity - Attack Surface - Cloud Weakness - Unauthorized Public Cloud Storage Exposure Detected
let timeFrame = 5m;
CyfirmaASCloudWeaknessAlerts_CL
| where severity == 'High' and TimeGenerated between (ago(timeFrame) .. now())
| extend
    Description=description,
    FirstSeen=first_seen,
    LastSeen=last_seen,
    RiskScore=risk_score,
    Domain=asset_name,
    AlertUID=alert_uid,
    UID=uid,
    Source=source,
    SourceType=source_type,
    CreatedDate=created_date,
    Impact=impact,
    ProviderName='CYFIRMA',
    ProductName='DeCYFIR/DeTCT'
| project
    TimeGenerated,
    Description,
    Domain,
    RiskScore,
    FirstSeen,
    LastSeen,
    AlertUID,
    UID,
    Source,
    SourceType,
    CreatedDate,
    Impact,
    ProviderName,
    ProductName

YAML

OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cyfirma Attack Surface/Analytic Rules/ASCloudWeaknessMediumRule.yaml
query: |
  // Medium Severity - Attack Surface - Cloud Weakness - Unauthorized Public Cloud Storage Exposure Detected
  let timeFrame = 5m;
  CyfirmaASCloudWeaknessAlerts_CL
  | where severity == 'High' and TimeGenerated between (ago(timeFrame) .. now())
  | extend
      Description=description,
      FirstSeen=first_seen,
      LastSeen=last_seen,
      RiskScore=risk_score,
      Domain=asset_name,
      AlertUID=alert_uid,
      UID=uid,
      Source=source,
      SourceType=source_type,
      CreatedDate=created_date,
      Impact=impact,
      ProviderName='CYFIRMA',
      ProductName='DeCYFIR/DeTCT'
  | project
      TimeGenerated,
      Description,
      Domain,
      RiskScore,
      FirstSeen,
      LastSeen,
      AlertUID,
      UID,
      Source,
      SourceType,
      CreatedDate,
      Impact,
      ProviderName,
      ProductName  
relevantTechniques:
- T1087
- T1087.004
kind: Scheduled
triggerThreshold: 0
triggerOperator: gt
tactics:
- InitialAccess
- Collection
- Discovery
- Exfiltration
requiredDataConnectors:
- dataTypes:
  - CyfirmaASCloudWeaknessAlerts_CL
  connectorId: CyfirmaAttackSurfaceAlertsConnector
queryFrequency: 5m
entityMappings:
- entityType: DNS
  fieldMappings:
  - identifier: DomainName
    columnName: Domain
version: 1.0.1
queryPeriod: 5m
customDetails:
  AlertUID: AlertUID
  RiskScore: RiskScore
  CreatedDate: CreatedDate
  FirstSeen: FirstSeen
  TimeGenerated: TimeGenerated
  Impact: Impact
  Source: Source
  LastSeen: LastSeen
  SourceType: SourceType
  UID: UID
severity: Medium
alertDetailsOverride:
  alertDisplayNameFormat: 'CYFIRMA - Medium Severity Alert - Unauthorized Public Cloud Storage Exposure Detected - Domain: {{Domain}}'
  alertDynamicProperties:
  - value: ProductName
    alertProperty: ProductName
  - value: ProviderName
    alertProperty: ProviderName
  alertDescriptionFormat: CYFIRMA - Medium Severity Alert - Unauthorized Public Cloud Storage Exposure Detected - {{Description}}
incidentConfiguration:
  createIncident: true
  groupingConfiguration:
    reopenClosedIncident: false
    lookbackDuration: PT5H
    matchingMethod: AllEntities
    enabled: false
name: CYFIRMA - Attack Surface - Cloud Weakness Medium Rule
id: b8a3c5e2-04d5-4b61-9b62-b4f53a417f74
eventGroupingSettings:
  aggregationKind: AlertPerResult
status: Available
description: |
  "This rule detects cloud storage buckets (e.g., AWS S3) that are publicly accessible without authentication. 
  Such misconfigurations can lead to data exfiltration, compliance violations, and reputational damage. 
  The detection is based on Cyfirma's Attack Surface Intelligence."

ARM