NGINX - Multiple client errors from single IP address

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Id	42771afe-edb3-4330-bc4a-abf6a5714454
Rulename	NGINX - Multiple client errors from single IP address
Description	Detects multiple client errors from one source in short timeframe
Severity	Medium
Tactics	InitialAccess
Techniques	T1190 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/NGINX HTTP Server/Analytic Rules/NGINXMultipleClientErrorsFromSingleIP.yaml
Version	1.0.2
Arm template	42771afe-edb3-4330-bc4a-abf6a5714454.json

KQL

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

YAML

tactics:
- InitialAccess
entityMappings:
- fieldMappings:
  - identifier: Address
    columnName: IPCustomEntity
  entityType: IP
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  
requiredDataConnectors:
- connectorId: CustomLogsAma
  dataTypes:
  - NGINX_CL
version: 1.0.2
queryFrequency: 1h
queryPeriod: 1h
description: |
    'Detects multiple client errors from one source in short timeframe'
id: 42771afe-edb3-4330-bc4a-abf6a5714454
triggerThreshold: 0
severity: Medium
kind: Scheduled
status: Available
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/NGINX HTTP Server/Analytic Rules/NGINXMultipleClientErrorsFromSingleIP.yaml
name: NGINX - Multiple client errors from single IP address
relevantTechniques:
- T1190
- T1133
triggerOperator: gt

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/42771afe-edb3-4330-bc4a-abf6a5714454')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/42771afe-edb3-4330-bc4a-abf6a5714454')]",
      "properties": {
        "alertRuleTemplateName": "42771afe-edb3-4330-bc4a-abf6a5714454",
        "customDetails": null,
        "description": "'Detects multiple client errors from one source in short timeframe'\n",
        "displayName": "NGINX - Multiple client errors from single IP address",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPCustomEntity",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/NGINX HTTP Server/Analytic Rules/NGINXMultipleClientErrorsFromSingleIP.yaml",
        "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",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1133",
          "T1190"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}