NGINX - Multiple client errors from single IP address

let threshold = 100;
NGINXHTTPServer
| where tolong(HttpStatusCode) >= 400 and tolong(HttpStatusCode) <= 499 
| summarize MultipleClientErrors = count() by SrcIpAddr, bin(TimeGenerated, 5m)
| where MultipleClientErrors > threshold
| extend IPCustomEntity = SrcIpAddr

triggerOperator: gt
id: 42771afe-edb3-4330-bc4a-abf6a5714454
queryFrequency: 1h
entityMappings:
- entityType: IP
  fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
requiredDataConnectors:
- dataTypes:
  - NGINXHTTPServer
  connectorId: NGINXHTTPServer
severity: Medium
triggerThreshold: 0
kind: Scheduled
status: Available
queryPeriod: 1h
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/NGINX HTTP Server/Analytic Rules/NGINXMultipleClientErrorsFromSingleIP.yaml
query: |
  let threshold = 100;
  NGINXHTTPServer
  | where tolong(HttpStatusCode) >= 400 and tolong(HttpStatusCode) <= 499 
  | summarize MultipleClientErrors = count() by SrcIpAddr, bin(TimeGenerated, 5m)
  | where MultipleClientErrors > threshold
  | extend IPCustomEntity = SrcIpAddr  
description: |
    'Detects multiple client errors from one source in short timeframe'
name: NGINX - Multiple client errors from single IP address
relevantTechniques:
- T1190
- T1133
tactics:
- InitialAccess
version: 1.0.0

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/42771afe-edb3-4330-bc4a-abf6a5714454')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/42771afe-edb3-4330-bc4a-abf6a5714454')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01",
      "properties": {
        "displayName": "NGINX - Multiple client errors from single IP address",
        "description": "'Detects multiple client errors from one source in short timeframe'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "let threshold = 100;\nNGINXHTTPServer\n| where tolong(HttpStatusCode) >= 400 and tolong(HttpStatusCode) <= 499 \n| summarize MultipleClientErrors = count() by SrcIpAddr, bin(TimeGenerated, 5m)\n| where MultipleClientErrors > threshold\n| extend IPCustomEntity = SrcIpAddr\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1190",
          "T1133"
        ],
        "alertRuleTemplateName": "42771afe-edb3-4330-bc4a-abf6a5714454",
        "customDetails": null,
        "entityMappings": [
          {
            "fieldMappings": [
              {
                "identifier": "Address",
                "columnName": "IPCustomEntity"
              }
            ],
            "entityType": "IP"
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/NGINX HTTP Server/Analytic Rules/NGINXMultipleClientErrorsFromSingleIP.yaml",
        "templateVersion": "1.0.0",
        "status": "Available"
      }
    }
  ]
}