PulseConnectSecure - Potential Brute Force Attempts

let threshold = 20;
PulseConnectSecure
| where Messages contains "Login failed"
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by User, Source_IP
| where count_ > threshold
| extend timestamp = StartTime, AccountCustomEntity = User, IPCustomEntity = Source_IP

queryFrequency: 1h
entityMappings:
- entityType: Account
  fieldMappings:
  - columnName: AccountCustomEntity
    identifier: FullName
- entityType: IP
  fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
severity: Low
triggerThreshold: 0
relevantTechniques:
- T1110
query: |
  let threshold = 20;
  PulseConnectSecure
  | where Messages contains "Login failed"
  | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by User, Source_IP
  | where count_ > threshold
  | extend timestamp = StartTime, AccountCustomEntity = User, IPCustomEntity = Source_IP  
id: 34663177-8abf-4db1-b0a4-5683ab273f44
triggerOperator: gt
version: 1.0.1
requiredDataConnectors:
- connectorId: PulseConnectSecure
  dataTypes:
  - Syslog
description: |
    'This query identifies evidence of potential brute force attack by looking at multiple failed attempts to log into the VPN server'
queryPeriod: 1h
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Pulse Connect Secure/Analytic Rules/PulseConnectSecureVPN-BruteForce.yaml
status: Available
name: PulseConnectSecure - Potential Brute Force Attempts
tactics:
- CredentialAccess
kind: Scheduled

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/34663177-8abf-4db1-b0a4-5683ab273f44')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/34663177-8abf-4db1-b0a4-5683ab273f44')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01",
      "properties": {
        "displayName": "PulseConnectSecure - Potential Brute Force Attempts",
        "description": "'This query identifies evidence of potential brute force attack by looking at multiple failed attempts to log into the VPN server'\n",
        "severity": "Low",
        "enabled": true,
        "query": "let threshold = 20;\nPulseConnectSecure\n| where Messages contains \"Login failed\"\n| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by User, Source_IP\n| where count_ > threshold\n| extend timestamp = StartTime, AccountCustomEntity = User, IPCustomEntity = Source_IP\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CredentialAccess"
        ],
        "techniques": [
          "T1110"
        ],
        "alertRuleTemplateName": "34663177-8abf-4db1-b0a4-5683ab273f44",
        "customDetails": null,
        "entityMappings": [
          {
            "entityType": "Account",
            "fieldMappings": [
              {
                "identifier": "FullName",
                "columnName": "AccountCustomEntity"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "identifier": "Address",
                "columnName": "IPCustomEntity"
              }
            ]
          }
        ],
        "status": "Available",
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Pulse Connect Secure/Analytic Rules/PulseConnectSecureVPN-BruteForce.yaml",
        "templateVersion": "1.0.1"
      }
    }
  ]
}