Cloudflare - Multiple user agents for single source | Microsoft Sentinel Analytic Rules

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Id	fc50076a-0275-43d5-b9dd-38346c061f68
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%20CCF/Analytic%20Rules/CloudflareCCFMultipleUAs.yaml
Version	1.0.1
Arm template	fc50076a-0275-43d5-b9dd-38346c061f68.json

KQL

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

YAML

entityMappings:
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: SrcIpAddr
name: Cloudflare - Multiple user agents for single source
kind: Scheduled
triggerOperator: gt
status: Available
queryPeriod: 1h
requiredDataConnectors:
- connectorId: CloudflareDataConnector
  dataTypes:
  - Cloudflare
tactics:
- InitialAccess
query: |
  let threshold = 10;
  Cloudflare
  | where isnotempty(HttpUserAgentOriginal)
  | summarize d_ua = dcount(HttpUserAgentOriginal) by SrcIpAddr, bin(TimeGenerated, 3m)
  | where d_ua > threshold
description: |
  'Detects requests with different user agents from one source in short timeframe.'
severity: Medium
id: fc50076a-0275-43d5-b9dd-38346c061f68
triggerThreshold: 0
queryFrequency: 1h
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cloudflare%20CCF/Analytic%20Rules/CloudflareCCFMultipleUAs.yaml
version: 1.0.1
relevantTechniques:
- T1190
- T1133

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-38346c061f68')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/fc50076a-0275-43d5-b9dd-38346c061f68')]",
      "properties": {
        "alertRuleTemplateName": "fc50076a-0275-43d5-b9dd-38346c061f68",
        "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": "SrcIpAddr",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cloudflare%20CCF/Analytic%20Rules/CloudflareCCFMultipleUAs.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",
        "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"
    }
  ]
}