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

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/b8a3c5e2-04d5-4b61-9b62-b4f53a417f74')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/b8a3c5e2-04d5-4b61-9b62-b4f53a417f74')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "CYFIRMA - Medium Severity Alert - Unauthorized Public Cloud Storage Exposure Detected - {{Description}}",
          "alertDisplayNameFormat": "CYFIRMA - Medium Severity Alert - Unauthorized Public Cloud Storage Exposure Detected - Domain: {{Domain}}",
          "alertDynamicProperties": [
            {
              "alertProperty": "ProductName",
              "value": "ProductName"
            },
            {
              "alertProperty": "ProviderName",
              "value": "ProviderName"
            }
          ]
        },
        "alertRuleTemplateName": "b8a3c5e2-04d5-4b61-9b62-b4f53a417f74",
        "customDetails": {
          "AlertUID": "AlertUID",
          "CreatedDate": "CreatedDate",
          "FirstSeen": "FirstSeen",
          "Impact": "Impact",
          "LastSeen": "LastSeen",
          "RiskScore": "RiskScore",
          "Source": "Source",
          "SourceType": "SourceType",
          "TimeGenerated": "TimeGenerated",
          "UID": "UID"
        },
        "description": "\"This rule detects cloud storage buckets (e.g., AWS S3) that are publicly accessible without authentication. \nSuch misconfigurations can lead to data exfiltration, compliance violations, and reputational damage. \nThe detection is based on Cyfirma's Attack Surface Intelligence.\"\n",
        "displayName": "CYFIRMA - Attack Surface - Cloud Weakness Medium Rule",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "DNS",
            "fieldMappings": [
              {
                "columnName": "Domain",
                "identifier": "DomainName"
              }
            ]
          }
        ],
        "eventGroupingSettings": {
          "aggregationKind": "AlertPerResult"
        },
        "incidentConfiguration": {
          "createIncident": true,
          "groupingConfiguration": {
            "enabled": false,
            "lookbackDuration": "PT5H",
            "matchingMethod": "AllEntities",
            "reopenClosedIncident": false
          }
        },
        "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\nlet timeFrame = 5m;\nCyfirmaASCloudWeaknessAlerts_CL\n| where severity == 'High' and TimeGenerated between (ago(timeFrame) .. now())\n| extend\n    Description=description,\n    FirstSeen=first_seen,\n    LastSeen=last_seen,\n    RiskScore=risk_score,\n    Domain=asset_name,\n    AlertUID=alert_uid,\n    UID=uid,\n    Source=source,\n    SourceType=source_type,\n    CreatedDate=created_date,\n    Impact=impact,\n    ProviderName='CYFIRMA',\n    ProductName='DeCYFIR/DeTCT'\n| project\n    TimeGenerated,\n    Description,\n    Domain,\n    RiskScore,\n    FirstSeen,\n    LastSeen,\n    AlertUID,\n    UID,\n    Source,\n    SourceType,\n    CreatedDate,\n    Impact,\n    ProviderName,\n    ProductName\n",
        "queryFrequency": "PT5M",
        "queryPeriod": "PT5M",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [
          "T1087.004"
        ],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Collection",
          "Discovery",
          "Exfiltration",
          "InitialAccess"
        ],
        "techniques": [
          "T1087"
        ],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}