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Id83a0b48f-1cb7-4b4f-a018-23c3203a239b
RulenameNGINX - Multiple user agents for single source
DescriptionDetects requests with different user agents from one source in short timeframe.
SeverityMedium
TacticsInitialAccess
TechniquesT1190
T1133
Required data connectorsCustomLogsAma
KindScheduled
Query frequency1h
Query period1h
Trigger threshold0
Trigger operatorgt
Source Urihttps://github.com/Azure/Azure-Sentinel/blob/master/Solutions/NGINX%20HTTP%20Server/Analytic%20Rules/NGINXDifferentUAsFromSingleIP.yaml
Version1.0.2
Arm template83a0b48f-1cb7-4b4f-a018-23c3203a239b.json
Deploy To Azure
let threshold = 5;
NGINXHTTPServer
| summarize makeset(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 5m)
| extend ua_count = array_length(set_HttpUserAgentOriginal)
| where ua_count > threshold
| extend IPCustomEntity = SrcIpAddr
name: NGINX - Multiple user agents for single source
requiredDataConnectors:
- dataTypes:
  - NGINX_CL
  connectorId: CustomLogsAma
tactics:
- InitialAccess
entityMappings:
- fieldMappings:
  - identifier: Address
    columnName: IPCustomEntity
  entityType: IP
relevantTechniques:
- T1190
- T1133
queryFrequency: 1h
severity: Medium
version: 1.0.2
description: |
  'Detects requests with different user agents from one source in short timeframe.'
id: 83a0b48f-1cb7-4b4f-a018-23c3203a239b
queryPeriod: 1h
triggerThreshold: 0
triggerOperator: gt
kind: Scheduled
query: |
  let threshold = 5;
  NGINXHTTPServer
  | summarize makeset(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 5m)
  | extend ua_count = array_length(set_HttpUserAgentOriginal)
  | where ua_count > threshold
  | extend IPCustomEntity = SrcIpAddr
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/NGINX%20HTTP%20Server/Analytic%20Rules/NGINXDifferentUAsFromSingleIP.yaml
status: Available
{
  "$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/83a0b48f-1cb7-4b4f-a018-23c3203a239b')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/83a0b48f-1cb7-4b4f-a018-23c3203a239b')]",
      "properties": {
        "alertRuleTemplateName": "83a0b48f-1cb7-4b4f-a018-23c3203a239b",
        "customDetails": null,
        "description": "'Detects requests with different user agents from one source in short timeframe.'\n",
        "displayName": "NGINX - Multiple user agents for single source",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPCustomEntity",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/NGINX%20HTTP%20Server/Analytic%20Rules/NGINXDifferentUAsFromSingleIP.yaml",
        "query": "let threshold = 5;\nNGINXHTTPServer\n| summarize makeset(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 5m)\n| extend ua_count = array_length(set_HttpUserAgentOriginal)\n| where ua_count > 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"
    }
  ]
}