Cloudflare - Multiple user agents for single source

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Id	fc50076a-0275-43d5-b9dd-38346c061f67
Rulename	Cloudflare - Multiple user agents for single source
Description	Detects requests with different user agents from one source in short timeframe.
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/CloudflareMultipleUAs.yaml
Version	1.0.0
Arm template	fc50076a-0275-43d5-b9dd-38346c061f67.json

KQL

let threshold = 10;
Cloudflare
| where isnotempty(HttpUserAgentOriginal)
| summarize d_ua = dcount(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 3m)
| where d_ua > threshold
| extend IPCustomEntity = SrcIpAddr

YAML

query: |
  let threshold = 10;
  Cloudflare
  | where isnotempty(HttpUserAgentOriginal)
  | summarize d_ua = dcount(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 3m)
  | where d_ua > threshold
  | extend IPCustomEntity = SrcIpAddr  
relevantTechniques:
- T1190
- T1133
name: Cloudflare - Multiple user agents for single source
severity: Medium
triggerThreshold: 0
description: |
    'Detects requests with different user agents from one source in short timeframe.'
status: Available
triggerOperator: gt
tactics:
- InitialAccess
entityMappings:
- fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
  entityType: IP
requiredDataConnectors:
- connectorId: CloudflareDataConnector
  dataTypes:
  - Cloudflare
id: fc50076a-0275-43d5-b9dd-38346c061f67
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cloudflare/Analytic Rules/CloudflareMultipleUAs.yaml
queryPeriod: 1h
queryFrequency: 1h
version: 1.0.0
kind: Scheduled

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/fc50076a-0275-43d5-b9dd-38346c061f67')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/fc50076a-0275-43d5-b9dd-38346c061f67')]",
      "properties": {
        "alertRuleTemplateName": "fc50076a-0275-43d5-b9dd-38346c061f67",
        "customDetails": null,
        "description": "'Detects requests with different user agents from one source in short timeframe.'\n",
        "displayName": "Cloudflare - 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/Cloudflare/Analytic Rules/CloudflareMultipleUAs.yaml",
        "query": "let threshold = 10;\nCloudflare\n| where isnotempty(HttpUserAgentOriginal)\n| summarize d_ua = dcount(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 3m)\n| where d_ua > 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": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}