Microsoft Sentinel Analytic Rules
cloudbrothers.infoAzure Sentinel RepoToggle Dark/Light/Auto modeToggle Dark/Light/Auto modeToggle Dark/Light/Auto modeBack to homepage

ClientDeniedAccess

Back
Ida9956d3a-07a9-44a6-a279-081a85020cae
RulenameClientDeniedAccess
DescriptionCreates an incident in the event a Client has an excessive amounts of denied access requests.
SeverityMedium
TacticsCredentialAccess
TechniquesT1110
Required data connectorsSymantecVIP
KindScheduled
Query frequency1h
Query period1h
Trigger threshold0
Trigger operatorgt
Source Urihttps://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Symantec VIP/Analytic Rules/ClientDeniedAccess.yaml
Version1.0.0
Arm templatea9956d3a-07a9-44a6-a279-081a85020cae.json
Deploy To Azure

let threshold = 15;
let rejectedAccess = SymantecVIP
| where isnotempty(RADIUSAuth)
| where RADIUSAuth =~ "Reject"
| summarize Total = count() by ClientIP, bin(TimeGenerated, 15m)
| where Total > threshold
| project ClientIP;
SymantecVIP
| where isnotempty(RADIUSAuth)
| where RADIUSAuth =~ "Reject"
| join kind=inner rejectedAccess on ClientIP
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by ClientIP, User
| extend timestamp = StartTime, IPCustomEntity = ClientIP, AccountCustomEntity = User
description: |
    'Creates an incident in the event a Client has an excessive amounts of denied access requests.'
relevantTechniques:
- T1110
queryPeriod: 1h
severity: Medium
triggerOperator: gt
kind: Scheduled
triggerThreshold: 0
version: 1.0.0
name: ClientDeniedAccess
queryFrequency: 1h
id: a9956d3a-07a9-44a6-a279-081a85020cae
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Symantec VIP/Analytic Rules/ClientDeniedAccess.yaml
entityMappings:
- fieldMappings:
  - columnName: AccountCustomEntity
    identifier: FullName
  entityType: Account
- fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
  entityType: IP
status: Available
tactics:
- CredentialAccess
requiredDataConnectors:
- dataTypes:
  - Syslog
  connectorId: SymantecVIP
query: |2

  let threshold = 15;
  let rejectedAccess = SymantecVIP
  | where isnotempty(RADIUSAuth)
  | where RADIUSAuth =~ "Reject"
  | summarize Total = count() by ClientIP, bin(TimeGenerated, 15m)
  | where Total > threshold
  | project ClientIP;
  SymantecVIP
  | where isnotempty(RADIUSAuth)
  | where RADIUSAuth =~ "Reject"
  | join kind=inner rejectedAccess on ClientIP
  | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by ClientIP, User
  | extend timestamp = StartTime, IPCustomEntity = ClientIP, AccountCustomEntity = User
{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "parameters": {
    "workspace": {
      "type": "String"
    }
  },
  "resources": [
    {
      "apiVersion": "2023-02-01-preview",
      "id": "[concat(resourceId('Microsoft.OperationalInsights/workspaces/providers', parameters('workspace'), 'Microsoft.SecurityInsights'),'/alertRules/a9956d3a-07a9-44a6-a279-081a85020cae')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/a9956d3a-07a9-44a6-a279-081a85020cae')]",
      "properties": {
        "alertRuleTemplateName": "a9956d3a-07a9-44a6-a279-081a85020cae",
        "customDetails": null,
        "description": "'Creates an incident in the event a Client has an excessive amounts of denied access requests.'\n",
        "displayName": "ClientDeniedAccess",
        "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/ClientDeniedAccess.yaml",
        "query": "\nlet threshold = 15;\nlet rejectedAccess = SymantecVIP\n| where isnotempty(RADIUSAuth)\n| where RADIUSAuth =~ \"Reject\"\n| summarize Total = count() by ClientIP, bin(TimeGenerated, 15m)\n| where Total > threshold\n| project ClientIP;\nSymantecVIP\n| where isnotempty(RADIUSAuth)\n| where RADIUSAuth =~ \"Reject\"\n| join kind=inner rejectedAccess on ClientIP\n| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by ClientIP, User\n| extend timestamp = StartTime, IPCustomEntity = ClientIP, AccountCustomEntity = User\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Medium",
        "status": "Available",
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CredentialAccess"
        ],
        "techniques": [
          "T1110"
        ],
        "templateVersion": "1.0.0",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}