CYFIRMA - Attack Surface - Cloud Weakness High Rule

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Id	87cd8b10-90f6-4967-a4a7-2142e848ec8f
Rulename	CYFIRMA - Attack Surface - Cloud Weakness High 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	High
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/ASCloudWeaknessHighRule.yaml
Version	1.0.1
Arm template	87cd8b10-90f6-4967-a4a7-2142e848ec8f.json

KQL

// High Severity - Attack Surface - Cloud Weakness - Unauthorized Public Cloud Storage Exposure Detected
let timeFrame = 5m;
CyfirmaASCloudWeaknessAlerts_CL
| where severity == 'Critical' 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

queryPeriod: 5m
query: |
  // High Severity - Attack Surface - Cloud Weakness - Unauthorized Public Cloud Storage Exposure Detected
  let timeFrame = 5m;
  CyfirmaASCloudWeaknessAlerts_CL
  | where severity == 'Critical' 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  
incidentConfiguration:
  groupingConfiguration:
    lookbackDuration: PT5H
    reopenClosedIncident: false
    matchingMethod: AllEntities
    enabled: false
  createIncident: true
name: CYFIRMA - Attack Surface - Cloud Weakness High Rule
entityMappings:
- fieldMappings:
  - columnName: Domain
    identifier: DomainName
  entityType: DNS
queryFrequency: 5m
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cyfirma Attack Surface/Analytic Rules/ASCloudWeaknessHighRule.yaml
alertDetailsOverride:
  alertDisplayNameFormat: 'CYFIRMA - High Severity Alert - Unauthorized Public Cloud Storage Exposure Detected - Domain: {{Domain}} '
  alertDescriptionFormat: 'CYFIRMA - High Severity Alert - Unauthorized Public Cloud Storage Exposure Detected - {{Description}} '
  alertDynamicProperties:
  - value: ProductName
    alertProperty: ProductName
  - value: ProviderName
    alertProperty: ProviderName
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."  
kind: Scheduled
version: 1.0.1
eventGroupingSettings:
  aggregationKind: AlertPerResult
status: Available
severity: High
requiredDataConnectors:
- connectorId: CyfirmaAttackSurfaceAlertsConnector
  dataTypes:
  - CyfirmaASCloudWeaknessAlerts_CL
triggerOperator: gt
triggerThreshold: 0
customDetails:
  SourceType: SourceType
  LastSeen: LastSeen
  UID: UID
  CreatedDate: CreatedDate
  FirstSeen: FirstSeen
  Impact: Impact
  RiskScore: RiskScore
  Source: Source
  TimeGenerated: TimeGenerated
  AlertUID: AlertUID
tactics:
- InitialAccess
- Collection
- Discovery
- Exfiltration
id: 87cd8b10-90f6-4967-a4a7-2142e848ec8f
relevantTechniques:
- T1087
- T1087.004

ARM