Cloudflare - Unexpected POST requests

Cloudflare
| where HttpRequestMethod in~ ('POST', 'PUT')
| where tostring(HttpStatusCode) startswith '2'
| where DstBytes != 0 or SrcBytes != 0
| extend fe = extract(@'.*(\.\w+)$', 1, ClientRequestURI)
| where fe in~ ('.jpg', '.jpeg', '.gif', '.png', '.icon', '.ico', '.xml', '.swf', '.svg', '.ppt', '.pttx', '.doc', '.docx', '.rtf', '.pdf', '.tif', '.zip', '.mov')
| extend IPCustomEntity = SrcIpAddr

relevantTechniques:
- T1505
- T1071
name: Cloudflare - Unexpected POST requests
requiredDataConnectors:
- dataTypes:
  - Cloudflare
  connectorId: CloudflareDataConnector
entityMappings:
- fieldMappings:
  - identifier: Address
    columnName: IPCustomEntity
  entityType: IP
triggerThreshold: 0
id: 7313352a-09f6-4a84-88bd-6f17f1cbeb8f
tactics:
- Persistence
- CommandAndControl
version: 1.0.0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cloudflare/Analytic Rules/CloudflareUnexpectedPost.yaml
queryPeriod: 1h
kind: Scheduled
queryFrequency: 1h
severity: Medium
status: Available
description: |
    'Detects post requests to unusual extensions.'
query: |
  Cloudflare
  | where HttpRequestMethod in~ ('POST', 'PUT')
  | where tostring(HttpStatusCode) startswith '2'
  | where DstBytes != 0 or SrcBytes != 0
  | extend fe = extract(@'.*(\.\w+)$', 1, ClientRequestURI)
  | where fe in~ ('.jpg', '.jpeg', '.gif', '.png', '.icon', '.ico', '.xml', '.swf', '.svg', '.ppt', '.pttx', '.doc', '.docx', '.rtf', '.pdf', '.tif', '.zip', '.mov')
  | extend IPCustomEntity = SrcIpAddr  
triggerOperator: gt

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2024-01-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/7313352a-09f6-4a84-88bd-6f17f1cbeb8f')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/7313352a-09f6-4a84-88bd-6f17f1cbeb8f')]",
      "properties": {
        "alertRuleTemplateName": "7313352a-09f6-4a84-88bd-6f17f1cbeb8f",
        "customDetails": null,
        "description": "'Detects post requests to unusual extensions.'\n",
        "displayName": "Cloudflare - Unexpected POST requests",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPCustomEntity",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Cloudflare/Analytic Rules/CloudflareUnexpectedPost.yaml",
        "query": "Cloudflare\n| where HttpRequestMethod in~ ('POST', 'PUT')\n| where tostring(HttpStatusCode) startswith '2'\n| where DstBytes != 0 or SrcBytes != 0\n| extend fe = extract(@'.*(\\.\\w+)$', 1, ClientRequestURI)\n| where fe in~ ('.jpg', '.jpeg', '.gif', '.png', '.icon', '.ico', '.xml', '.swf', '.svg', '.ppt', '.pttx', '.doc', '.docx', '.rtf', '.pdf', '.tif', '.zip', '.mov')\n| extend IPCustomEntity = SrcIpAddr\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl",
          "Persistence"
        ],
        "techniques": [
          "T1071",
          "T1505"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}