Excessive Failed Authentication from Invalid Inputs

let threshold = 15;
SymantecVIP
| where isnotempty(RADIUSAuth)
| where RADIUSAuth =~ "Reject"
| summarize Total = count() by bin(TimeGenerated, 15m), User, ClientIP
| where Total > threshold
| extend timestamp = TimeGenerated, IPCustomEntity = ClientIP, AccountCustomEntity = User

relevantTechniques:
- T1110
name: Excessive Failed Authentication from Invalid Inputs
requiredDataConnectors:
- dataTypes:
  - Syslog
  connectorId: SymantecVIP
- datatypes:
  - Syslog
  connectorId: SyslogAma
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: AccountCustomEntity
  entityType: Account
- fieldMappings:
  - identifier: Address
    columnName: IPCustomEntity
  entityType: IP
triggerThreshold: 0
id: c775a46b-21b1-46d7-afa6-37e3e577a27b
tactics:
- CredentialAccess
version: 1.0.2
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Symantec VIP/Analytic Rules/ExcessiveFailedAuthenticationsfromInvalidInputs.yaml
queryPeriod: 1h
kind: Scheduled
queryFrequency: 1h
severity: Medium
status: Available
description: |
    'Creates an incident in the event that a user generates an excessive amount of failed authentications due to invalid inputs, indications of a potential brute force.'
query: |
  let threshold = 15;
  SymantecVIP
  | where isnotempty(RADIUSAuth)
  | where RADIUSAuth =~ "Reject"
  | summarize Total = count() by bin(TimeGenerated, 15m), User, ClientIP
  | where Total > threshold
  | extend timestamp = TimeGenerated, IPCustomEntity = ClientIP, AccountCustomEntity = User  
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/c775a46b-21b1-46d7-afa6-37e3e577a27b')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/c775a46b-21b1-46d7-afa6-37e3e577a27b')]",
      "properties": {
        "alertRuleTemplateName": "c775a46b-21b1-46d7-afa6-37e3e577a27b",
        "customDetails": null,
        "description": "'Creates an incident in the event that a user generates an excessive amount of failed authentications due to invalid inputs, indications of a potential brute force.'\n",
        "displayName": "Excessive Failed Authentication from Invalid Inputs",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "columnName": "AccountCustomEntity",
                "identifier": "FullName"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPCustomEntity",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Symantec VIP/Analytic Rules/ExcessiveFailedAuthenticationsfromInvalidInputs.yaml",
        "query": "let threshold = 15;\nSymantecVIP\n| where isnotempty(RADIUSAuth)\n| where RADIUSAuth =~ \"Reject\"\n| summarize Total = count() by bin(TimeGenerated, 15m), User, ClientIP\n| where Total > threshold\n| extend timestamp = TimeGenerated, IPCustomEntity = ClientIP, AccountCustomEntity = User\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CredentialAccess"
        ],
        "techniques": [
          "T1110"
        ],
        "templateVersion": "1.0.2",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}