CTERA Mass Access Denied Detection Analytic

id: 88341fc3-38e1-46db-8bb1-6c052e749991
name: CTERA Mass Access Denied Detection Analytic
description: 'This analytic rule detects and alerts when access denied operations generated by the CTERA Edge Filer goes over a predefined threshold'
kind: Scheduled
severity: High
status: Available
requiredDataConnectors:
  - connectorId: CTERA
    dataTypes:
      - Syslog
queryFrequency: 5m
queryPeriod: 5m
triggerOperator: GreaterThan
triggerThreshold: 1000
tactics:
  - DefenseEvasion
relevantTechniques:
  - T1562
query: |
  Syslog
  | where ProcessName == 'gw-audit'
  | extend
      TenantName = extract("\"vportal\":\"([^\"]*)\"", 1, SyslogMessage),
      UserName = extract("user=([^|]*)", 1, SyslogMessage),
      Operation = extract("op=([^|]*)", 1, SyslogMessage),
      EdgeFiler = extract("\"client\":\"([^\"]*)\"", 1, SyslogMessage),
      RootPath = extract("rootPath=([^|]*)", 1, SyslogMessage),
      Share = extract("share=([^|]*)", 1, SyslogMessage),
      LocalPath = extract("path=([^|]*)", 1, SyslogMessage),
      Timestamp = todatetime(extract("\"@timestamp\":\"([^\"]*)\"", 1, SyslogMessage))
  | where Operation in ('OpenDenied', 'createDenied', 'AclDenied', 'deleteDenied')
  | summarize Count = count() by bin(Timestamp, 5m), UserName, EdgeFiler
  | where Count > 1000
incidentConfiguration:
    createIncident: true
    groupingConfiguration:
        enabled: false
        reopenClosedIncident: false
        lookbackDuration: PT5H
        matchingMethod: AllEntities
eventGroupingSettings:
    aggregationKind: SingleAlert
alertDetailsOverride:
    alertnameFormat: 'CTERA Batch Access Denied Detection'
    alertDescriptionFormat: >
      Detected {{Count}} denied access attempts by user {{UserName}} on Edge Filer 
      {{EdgeFiler}} within 5 minutes. Please investigate unauthorized access attempts or misconfigurations.
customDetails:
    TenantName: TenantName
    UserName: UserName
    EdgeFiler: EdgeFiler
    RootPath: RootPath
    Share: Share
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: UserName
  - entityType: File
    fieldMappings:
      - identifier: Name
        columnName: EdgeFiler
suppressionDuration: PT5H
suppressionEnabled: false
version: 1.0.0