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	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	1.0.0
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

severity: Medium
relevantTechniques:
- T1190
- T1133
queryFrequency: 1h
kind: Scheduled
version: 1.0.0
name: NGINX - Multiple client errors from single IP address
triggerOperator: gt
description: |
    'Detects multiple client errors from one source in short timeframe'
queryPeriod: 1h
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  
entityMappings:
- entityType: IP
  fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
tactics:
- InitialAccess
status: Available
triggerThreshold: 0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/NGINX HTTP Server/Analytic Rules/NGINXMultipleClientErrorsFromSingleIP.yaml
id: 42771afe-edb3-4330-bc4a-abf6a5714454
requiredDataConnectors:
- dataTypes:
  - NGINXHTTPServer
  connectorId: NGINXHTTPServer

ARM

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-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",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1133",
          "T1190"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}