Ping Federate - Unexpected authentication URL

let known_domains = 
PingFederateEvent
| where TimeGenerated between (ago(14d) .. (1d))
| where isnotempty(DeviceCustomString1)
| extend url_parsed = parse_url(DeviceCustomString1)
| extend url_domain = extract(@'.*\.(.*\.[a-z]+)', 1, tostring(url_parsed.Host))
| summarize makeset(url_domain);
PingFederateEvent
| where isnotempty(DeviceCustomString1)
| extend url_parsed = parse_url(DeviceCustomString1)
| extend url_domain = extract(@'.*\.(.*\.[a-z]+)', 1, tostring(url_parsed.Host))
| where url_domain !in (known_domains)
| extend AccountCustomEntity = DstUserName
| extend IpCustomEntity = SrcIpAddr

kind: Scheduled
severity: Medium
entityMappings:
- fieldMappings:
  - identifier: Name
    columnName: AccountCustomEntity
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: IpCustomEntity
  entityType: IP
name: Ping Federate - Unexpected authentication URL.
relevantTechniques:
- T1078
triggerOperator: gt
tactics:
- InitialAccess
query: |
  let known_domains = 
  PingFederateEvent
  | where TimeGenerated between (ago(14d) .. (1d))
  | where isnotempty(DeviceCustomString1)
  | extend url_parsed = parse_url(DeviceCustomString1)
  | extend url_domain = extract(@'.*\.(.*\.[a-z]+)', 1, tostring(url_parsed.Host))
  | summarize makeset(url_domain);
  PingFederateEvent
  | where isnotempty(DeviceCustomString1)
  | extend url_parsed = parse_url(DeviceCustomString1)
  | extend url_domain = extract(@'.*\.(.*\.[a-z]+)', 1, tostring(url_parsed.Host))
  | where url_domain !in (known_domains)
  | extend AccountCustomEntity = DstUserName
  | extend IpCustomEntity = SrcIpAddr  
triggerThreshold: 0
status: Available
description: |
    'Detects unexpected authentication URL.'
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/PingFederate/Analytic Rules/PingFederateUnexpectedAuthUrl.yaml
queryFrequency: 1h
queryPeriod: 14d
id: 9578ef7f-cbb4-4e9a-bd26-37c15c53b413
requiredDataConnectors:
- connectorId: CefAma
  dataTypes:
  - CommonSecurityLog
version: 1.0.3

{
  "$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/9578ef7f-cbb4-4e9a-bd26-37c15c53b413')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/9578ef7f-cbb4-4e9a-bd26-37c15c53b413')]",
      "properties": {
        "alertRuleTemplateName": "9578ef7f-cbb4-4e9a-bd26-37c15c53b413",
        "customDetails": null,
        "description": "'Detects unexpected authentication URL.'\n",
        "displayName": "Ping Federate - Unexpected authentication URL.",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "Name"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IpCustomEntity",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/PingFederate/Analytic Rules/PingFederateUnexpectedAuthUrl.yaml",
        "query": "let known_domains = \nPingFederateEvent\n| where TimeGenerated between (ago(14d) .. (1d))\n| where isnotempty(DeviceCustomString1)\n| extend url_parsed = parse_url(DeviceCustomString1)\n| extend url_domain = extract(@'.*\\.(.*\\.[a-z]+)', 1, tostring(url_parsed.Host))\n| summarize makeset(url_domain);\nPingFederateEvent\n| where isnotempty(DeviceCustomString1)\n| extend url_parsed = parse_url(DeviceCustomString1)\n| extend url_domain = extract(@'.*\\.(.*\\.[a-z]+)', 1, tostring(url_parsed.Host))\n| where url_domain !in (known_domains)\n| extend AccountCustomEntity = DstUserName\n| extend IpCustomEntity = SrcIpAddr\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "InitialAccess"
        ],
        "techniques": [
          "T1078"
        ],
        "templateVersion": "1.0.3",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}