Zscaler - Unexpected event count of rejects by policy

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Id	593e3e2a-43ce-11ec-81d3-0242ac130003
Rulename	Zscaler - Unexpected event count of rejects by policy
Description	Detects unexpected event count of rejects by policy.
Severity	High
Tactics	InitialAccess
Techniques	T1078 T1133
Required data connectors	CustomLogsAma
Kind	Scheduled
Query frequency	1h
Query period	1h
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Zscaler Private Access (ZPA)/Analytic Rules/ZscalerUnexpectedCountEventResult.yaml
Version	1.0.2
Arm template	593e3e2a-43ce-11ec-81d3-0242ac130003.json

KQL

let threshold = 1000;
ZPAEvent
| where EventResult has "REJECTED_BY_POLICY"
| summarize rejected = count() by EventResult, DstUserName
| where rejected > threshold
| extend AccountCustomEntity = DstUserName

YAML

OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Zscaler Private Access (ZPA)/Analytic Rules/ZscalerUnexpectedCountEventResult.yaml
queryFrequency: 1h
name: Zscaler - Unexpected event count of rejects by policy
severity: High
triggerThreshold: 0
query: |
  let threshold = 1000;
  ZPAEvent
  | where EventResult has "REJECTED_BY_POLICY"
  | summarize rejected = count() by EventResult, DstUserName
  | where rejected > threshold
  | extend AccountCustomEntity = DstUserName  
requiredDataConnectors:
- datatypes:
  - ZPA_CL
  connectorId: CustomLogsAma
relevantTechniques:
- T1078
- T1133
status: Available
triggerOperator: gt
queryPeriod: 1h
description: |
    'Detects unexpected event count of rejects by policy.'
id: 593e3e2a-43ce-11ec-81d3-0242ac130003
version: 1.0.2
entityMappings:
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: Name
  entityType: Account
kind: Scheduled
tactics:
- InitialAccess

ARM