Cloudflare - Empty user agent
| Id | 729c6d21-fad9-4a6a-9c7f-482393c95957 | 
| Rulename | Cloudflare - Empty user agent | 
| Description | Detects requests where user agent is empty. | 
| Severity | Medium | 
| Tactics | InitialAccess | 
| Techniques | T1190 T1133 | 
| Required data connectors | CloudflareDataConnector | 
| 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/Cloudflare/Analytic Rules/CloudflareEmptyUA.yaml | 
| Version | 1.0.0 | 
| Arm template | 729c6d21-fad9-4a6a-9c7f-482393c95957.json | 
Cloudflare
| where isempty(HttpUserAgentOriginal)
| extend IPCustomEntity = SrcIpAddr
kind: Scheduled
entityMappings:
- entityType: IP
  fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
description: |
    'Detects requests where user agent is empty.'
severity: Medium
queryFrequency: 1h
triggerThreshold: 0
relevantTechniques:
- T1190
- T1133
status: Available
tactics:
- InitialAccess
name: Cloudflare - Empty user agent
id: 729c6d21-fad9-4a6a-9c7f-482393c95957
query: |
  Cloudflare
  | where isempty(HttpUserAgentOriginal)
  | extend IPCustomEntity = SrcIpAddr  
requiredDataConnectors:
- dataTypes:
  - Cloudflare
  connectorId: CloudflareDataConnector
version: 1.0.0
triggerOperator: gt
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cloudflare/Analytic Rules/CloudflareEmptyUA.yaml
queryPeriod: 1h
{
  "$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/729c6d21-fad9-4a6a-9c7f-482393c95957')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/729c6d21-fad9-4a6a-9c7f-482393c95957')]",
      "properties": {
        "alertRuleTemplateName": "729c6d21-fad9-4a6a-9c7f-482393c95957",
        "customDetails": null,
        "description": "'Detects requests where user agent is empty.'\n",
        "displayName": "Cloudflare - Empty user agent",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPCustomEntity",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cloudflare/Analytic Rules/CloudflareEmptyUA.yaml",
        "query": "Cloudflare\n| where isempty(HttpUserAgentOriginal)\n| extend IPCustomEntity = SrcIpAddr\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1133",
          "T1190"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}