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

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

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/87cd8b10-90f6-4967-a4a7-2142e848ec8f')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/87cd8b10-90f6-4967-a4a7-2142e848ec8f')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "CYFIRMA - High Severity Alert - Unauthorized Public Cloud Storage Exposure Detected - {{Description}} ",
          "alertDisplayNameFormat": "CYFIRMA - High Severity Alert - Unauthorized Public Cloud Storage Exposure Detected - Domain: {{Domain}} ",
          "alertDynamicProperties": [
            {
              "alertProperty": "ProductName",
              "value": "ProductName"
            },
            {
              "alertProperty": "ProviderName",
              "value": "ProviderName"
            }
          ]
        },
        "alertRuleTemplateName": "87cd8b10-90f6-4967-a4a7-2142e848ec8f",
        "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 High 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/ASCloudWeaknessHighRule.yaml",
        "query": "// High Severity - Attack Surface - Cloud Weakness - Unauthorized Public Cloud Storage Exposure Detected\nlet timeFrame = 5m;\nCyfirmaASCloudWeaknessAlerts_CL\n| where severity == 'Critical' 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": "High",
        "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"
    }
  ]
}