Cisco WSA - Multiple errors to resource from risky category

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Id	ebf9db0c-ba7b-4249-b9ec-50a05fa7c7c9
Rulename	Cisco WSA - Multiple errors to resource from risky category
Description	Detects multiple connection errors to resource from risky category.
Severity	Medium
Tactics	InitialAccess CommandAndControl
Techniques	T1189 T1102
Required data connectors	SyslogAma
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/CiscoWSA/Analytic Rules/CiscoWSAMultipleErrorsToUnwantedCategory.yaml
Version	1.0.2
Arm template	ebf9db0c-ba7b-4249-b9ec-50a05fa7c7c9.json

KQL

let threshold = 10;
let risky_sites = dynamic(['IW_adlt', 'IW_hack', 'IW_porn']);
CiscoWSAEvent
| where DvcAction startswith 'BLOCK_'
| where UrlCategory in~ (risky_sites)
| summarize count() by SrcUserName, UrlOriginal, bin(TimeGenerated, 5m)
| where count_ >= threshold
| extend URLCustomEntity = UrlOriginal, AccountCustomEntity = SrcUserName

YAML

OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CiscoWSA/Analytic Rules/CiscoWSAMultipleErrorsToUnwantedCategory.yaml
queryPeriod: 1h
kind: Scheduled
name: Cisco WSA - Multiple errors to resource from risky category
status: Available
entityMappings:
- fieldMappings:
  - columnName: URLCustomEntity
    identifier: Url
  entityType: URL
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: Name
  entityType: Account
tactics:
- InitialAccess
- CommandAndControl
description: |
    'Detects multiple connection errors to resource from risky category.'
severity: Medium
requiredDataConnectors:
- connectorId: SyslogAma
  datatypes:
  - Syslog
queryFrequency: 1h
triggerThreshold: 0
version: 1.0.2
query: |
  let threshold = 10;
  let risky_sites = dynamic(['IW_adlt', 'IW_hack', 'IW_porn']);
  CiscoWSAEvent
  | where DvcAction startswith 'BLOCK_'
  | where UrlCategory in~ (risky_sites)
  | summarize count() by SrcUserName, UrlOriginal, bin(TimeGenerated, 5m)
  | where count_ >= threshold
  | extend URLCustomEntity = UrlOriginal, AccountCustomEntity = SrcUserName  
relevantTechniques:
- T1189
- T1102
id: ebf9db0c-ba7b-4249-b9ec-50a05fa7c7c9
triggerOperator: gt

ARM