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

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

ARM