CYFIRMA - Attack Surface - Cloud Weakness Medium Rule

Back


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

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

ARM