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 NGINXHTTPServer
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	1.0.1
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

entityMappings:
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: IPCustomEntity
queryFrequency: 1h
name: NGINX - Multiple client errors from single IP address
kind: Scheduled
tactics:
- InitialAccess
triggerThreshold: 0
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  
relevantTechniques:
- T1190
- T1133
triggerOperator: gt
queryPeriod: 1h
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/NGINX HTTP Server/Analytic Rules/NGINXMultipleClientErrorsFromSingleIP.yaml
severity: Medium
status: Available
id: 42771afe-edb3-4330-bc4a-abf6a5714454
requiredDataConnectors:
- connectorId: NGINXHTTPServer
  dataTypes:
  - NGINXHTTPServer
- connectorId: CustomLogsAma
  dataTypes:
  - NGINX_CL
version: 1.0.1
description: |
    'Detects multiple client errors from one source in short timeframe'

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": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}