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

severity: High
triggerOperator: gt
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Zscaler Private Access (ZPA)/Analytic Rules/ZscalerUnexpectedCountEventResult.yaml
id: 593e3e2a-43ce-11ec-81d3-0242ac130003
entityMappings:
- fieldMappings:
  - identifier: Name
    columnName: AccountCustomEntity
  entityType: Account
kind: Scheduled
status: Available
tactics:
- InitialAccess
queryFrequency: 1h
requiredDataConnectors:
- connectorId: CustomLogsAma
  datatypes:
  - ZPA_CL
relevantTechniques:
- T1078
- T1133
version: 1.0.2
description: |
    'Detects unexpected event count of rejects by policy.'
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  
queryPeriod: 1h
name: Zscaler - Unexpected event count of rejects by policy

ARM