CTERA Mass Deletions Detection Analytic

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Id	5365f294-0c67-432a-bacf-b1282a3b6c46
Rulename	CTERA Mass Deletions Detection Analytic
Description	This analytic rule detects and alerts when large amount of deletion operations generated by the CTERA Edge Filer
Severity	High
Tactics	Impact
Techniques	T1485
Required data connectors	CTERA
Kind	Scheduled
Query frequency	5m
Query period	5m
Trigger threshold	5000
Trigger operator	GreaterThan
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CTERA/Analytic Rules/MassDeletions.yaml
Version	1.0.0
Arm template	5365f294-0c67-432a-bacf-b1282a3b6c46.json

KQL

Syslog
| where ProcessName == 'gw-audit'
| extend
    TenantName = extract("\"vportal\":\"([^\"]*)\"", 1, SyslogMessage),
    UserName = extract("user=([^|]*)", 1, SyslogMessage),
    Permission = 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 Permission == 'delete'
| summarize Count = count() by UserName, bin(Timestamp, 5m)
| where Count > 5000

YAML

tactics:
- Impact
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.
description: This analytic rule detects and alerts when large amount of deletion operations generated by the CTERA Edge Filer
entityMappings:
- entityType: Account
  fieldMappings:
  - identifier: Name
    columnName: UserName
- entityType: File
  fieldMappings:
  - identifier: Name
    columnName: EdgeFiler
suppressionDuration: PT5H
triggerThreshold: 5000
query: |
  Syslog
  | where ProcessName == 'gw-audit'
  | extend
      TenantName = extract("\"vportal\":\"([^\"]*)\"", 1, SyslogMessage),
      UserName = extract("user=([^|]*)", 1, SyslogMessage),
      Permission = 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 Permission == 'delete'
  | summarize Count = count() by UserName, bin(Timestamp, 5m)
  | where Count > 5000  
version: 1.0.0
requiredDataConnectors:
- connectorId: CTERA
  dataTypes:
  - Syslog
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CTERA/Analytic Rules/MassDeletions.yaml
queryFrequency: 5m
queryPeriod: 5m
incidentConfiguration:
  groupingConfiguration:
    matchingMethod: AllEntities
    enabled: false
    reopenClosedIncident: false
    lookbackDuration: PT5H
  createIncident: true
customDetails:
  TenantName: TenantName
  Share: Share
  RootPath: RootPath
  EdgeFiler: EdgeFiler
  UserName: UserName
severity: High
name: CTERA Mass Deletions Detection Analytic
triggerOperator: GreaterThan
id: 5365f294-0c67-432a-bacf-b1282a3b6c46
suppressionEnabled: false
status: Available
kind: Scheduled
relevantTechniques:
- T1485

ARM