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

status: Available
queryFrequency: 5m
suppressionEnabled: false
queryPeriod: 5m
triggerOperator: GreaterThan
alertDetailsOverride:
  alertDescriptionFormat: |
        Detected {{Count}} denied access attempts by user {{UserName}} on Edge Filer  {{EdgeFiler}} within 5 minutes. Please investigate unauthorized access attempts or misconfigurations.
  alertnameFormat: CTERA Batch Access Denied Detection
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  
eventGroupingSettings:
  aggregationKind: SingleAlert
suppressionDuration: PT5H
tactics:
- Impact
triggerThreshold: 5000
entityMappings:
- entityType: Account
  fieldMappings:
  - identifier: Name
    columnName: UserName
- entityType: File
  fieldMappings:
  - identifier: Name
    columnName: EdgeFiler
requiredDataConnectors:
- connectorId: CTERA
  dataTypes:
  - Syslog
kind: Scheduled
relevantTechniques:
- T1485
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CTERA/Analytic Rules/MassDeletions.yaml
customDetails:
  EdgeFiler: EdgeFiler
  Share: Share
  TenantName: TenantName
  RootPath: RootPath
  UserName: UserName
description: This analytic rule detects and alerts when large amount of deletion operations generated by the CTERA Edge Filer
incidentConfiguration:
  groupingConfiguration:
    matchingMethod: AllEntities
    reopenClosedIncident: false
    lookbackDuration: PT5H
    enabled: false
  createIncident: true
name: CTERA Mass Deletions Detection Analytic
version: 1.0.0
id: 5365f294-0c67-432a-bacf-b1282a3b6c46
severity: High

ARM