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	CiscoWSA 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	1.0.1
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

entityMappings:
- entityType: URL
  fieldMappings:
  - columnName: URLCustomEntity
    identifier: Url
- entityType: Account
  fieldMappings:
  - columnName: AccountCustomEntity
    identifier: Name
tactics:
- InitialAccess
- CommandAndControl
triggerOperator: gt
description: |
    'Detects multiple connection errors to resource from risky category.'
requiredDataConnectors:
- connectorId: CiscoWSA
  dataTypes:
  - CiscoWSAEvent
- connectorId: SyslogAma
  datatypes:
  - Syslog
relevantTechniques:
- T1189
- T1102
version: 1.0.1
id: ebf9db0c-ba7b-4249-b9ec-50a05fa7c7c9
kind: Scheduled
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  
status: Available
triggerThreshold: 0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CiscoWSA/Analytic Rules/CiscoWSAMultipleErrorsToUnwantedCategory.yaml
queryFrequency: 1h
severity: Medium
name: Cisco WSA - Multiple errors to resource from risky category
queryPeriod: 1h

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/ebf9db0c-ba7b-4249-b9ec-50a05fa7c7c9')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/ebf9db0c-ba7b-4249-b9ec-50a05fa7c7c9')]",
      "properties": {
        "alertRuleTemplateName": "ebf9db0c-ba7b-4249-b9ec-50a05fa7c7c9",
        "customDetails": null,
        "description": "'Detects multiple connection errors to resource from risky category.'\n",
        "displayName": "Cisco WSA - Multiple errors to resource from risky category",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "URL",
            "fieldMappings": [
              {
                "columnName": "URLCustomEntity",
                "identifier": "Url"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "Name"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/CiscoWSA/Analytic Rules/CiscoWSAMultipleErrorsToUnwantedCategory.yaml",
        "query": "let threshold = 10;\nlet risky_sites = dynamic(['IW_adlt', 'IW_hack', 'IW_porn']);\nCiscoWSAEvent\n| where DvcAction startswith 'BLOCK_'\n| where UrlCategory in~ (risky_sites)\n| summarize count() by SrcUserName, UrlOriginal, bin(TimeGenerated, 5m)\n| where count_ >= threshold\n| extend URLCustomEntity = UrlOriginal, AccountCustomEntity = SrcUserName\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl",
          "InitialAccess"
        ],
        "techniques": [
          "T1102",
          "T1189"
        ],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}