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

kind: Scheduled
incidentConfiguration:
  groupingConfiguration:
    matchingMethod: AllEntities
    enabled: false
    reopenClosedIncident: false
    lookbackDuration: PT5H
  createIncident: true
requiredDataConnectors:
- connectorId: CyfirmaAttackSurfaceAlertsConnector
  dataTypes:
  - CyfirmaASCloudWeaknessAlerts_CL
relevantTechniques:
- T1087
- T1087.004
entityMappings:
- entityType: DNS
  fieldMappings:
  - identifier: DomainName
    columnName: Domain
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  
triggerThreshold: 0
customDetails:
  Source: Source
  Impact: Impact
  TimeGenerated: TimeGenerated
  AlertUID: AlertUID
  FirstSeen: FirstSeen
  RiskScore: RiskScore
  UID: UID
  SourceType: SourceType
  LastSeen: LastSeen
  CreatedDate: CreatedDate
alertDetailsOverride:
  alertDynamicProperties:
  - alertProperty: ProductName
    value: ProductName
  - alertProperty: ProviderName
    value: ProviderName
  alertDisplayNameFormat: 'CYFIRMA - Medium Severity Alert - Unauthorized Public Cloud Storage Exposure Detected - Domain: {{Domain}}'
  alertDescriptionFormat: CYFIRMA - Medium Severity Alert - Unauthorized Public Cloud Storage Exposure Detected - {{Description}}
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cyfirma Attack Surface/Analytic Rules/ASCloudWeaknessMediumRule.yaml
queryPeriod: 5m
tactics:
- InitialAccess
- Collection
- Discovery
- Exfiltration
name: CYFIRMA - Attack Surface - Cloud Weakness Medium Rule
status: Available
eventGroupingSettings:
  aggregationKind: AlertPerResult
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."  
id: b8a3c5e2-04d5-4b61-9b62-b4f53a417f74
version: 1.0.1
triggerOperator: gt
queryFrequency: 5m
severity: Medium

ARM