API - Rate limiting

let firstRec = apifirewall_log_1_CL
| where TimeGenerated >= ago(5m) 
| project-away Non_blocking_mode_b, Source_Port_d, Destination_Port_d, Query_s, API_ID_g, Request_Header_s, Response_Header_s, Errors_s, Type, UUID_g
| where Instance_Name_s == "Instance_8" and URI_Path_s has "/api/login" and Status_d == 429;
let rateLimitCount = (toscalar(firstRec | count));
let recCount = iff((rateLimitCount > 20), 1, 0);
firstRec | top recCount by Timestamp_t desc;

relevantTechniques:
- T1499
name: API - Rate limiting
requiredDataConnectors:
- dataTypes:
  - apifirewall_log_1_CL
  connectorId: 42CrunchAPIProtection
entityMappings:
- fieldMappings:
  - identifier: Address
    columnName: Source_IP_s
  entityType: IP
- fieldMappings:
  - identifier: HostName
    columnName: Hostname_s
  entityType: Host
- fieldMappings:
  - identifier: FullName
    columnName: Instance_Name_s
  entityType: Account
triggerThreshold: 0
id: b808063b-07d5-432c-95d0-8900da61cce9
tactics:
- Impact
version: 1.0.1
customDetails: 
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/42Crunch API Protection/Analytic Rules/APIRateLimiting.yaml
queryPeriod: 5m
kind: Scheduled
eventGroupingSettings:
  aggregationKind: SingleAlert
queryFrequency: 5m
severity: Medium
status: Available
description: |
    '42Crunch API protection against rate limiting'
query: |
  let firstRec = apifirewall_log_1_CL
  | where TimeGenerated >= ago(5m) 
  | project-away Non_blocking_mode_b, Source_Port_d, Destination_Port_d, Query_s, API_ID_g, Request_Header_s, Response_Header_s, Errors_s, Type, UUID_g
  | where Instance_Name_s == "Instance_8" and URI_Path_s has "/api/login" and Status_d == 429;
  let rateLimitCount = (toscalar(firstRec | count));
  let recCount = iff((rateLimitCount > 20), 1, 0);
  firstRec | top recCount by Timestamp_t desc;  
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/b808063b-07d5-432c-95d0-8900da61cce9')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/b808063b-07d5-432c-95d0-8900da61cce9')]",
      "properties": {
        "alertRuleTemplateName": "b808063b-07d5-432c-95d0-8900da61cce9",
        "customDetails": null,
        "description": "'42Crunch API protection against rate limiting'\n",
        "displayName": "API - Rate limiting",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "Source_IP_s",
                "identifier": "Address"
              }
            ]
          },
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "Hostname_s",
                "identifier": "HostName"
              }
            ]
          },
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "Instance_Name_s",
                "identifier": "FullName"
              }
            ]
          }
        ],
        "eventGroupingSettings": {
          "aggregationKind": "SingleAlert"
        },
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/42Crunch API Protection/Analytic Rules/APIRateLimiting.yaml",
        "query": "let firstRec = apifirewall_log_1_CL\n| where TimeGenerated >= ago(5m) \n| project-away Non_blocking_mode_b, Source_Port_d, Destination_Port_d, Query_s, API_ID_g, Request_Header_s, Response_Header_s, Errors_s, Type, UUID_g\n| where Instance_Name_s == \"Instance_8\" and URI_Path_s has \"/api/login\" and Status_d == 429;\nlet rateLimitCount = (toscalar(firstRec | count));\nlet recCount = iff((rateLimitCount > 20), 1, 0);\nfirstRec | top recCount by Timestamp_t desc;\n",
        "queryFrequency": "PT5M",
        "queryPeriod": "PT5M",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "Impact"
        ],
        "techniques": [
          "T1499"
        ],
        "templateVersion": "1.0.1",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}