Excessive Denied Proxy Traffic

let threshold = 100;
SymantecProxySG
| where sc_filter_result =~ "DENIED"
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by c_ip, cs_host
| where count_ > threshold
| extend timestamp = StartTime, HostCustomEntity = cs_host, IPCustomEntity = c_ip

relevantTechniques:
- T1090
- T1562
name: Excessive Denied Proxy Traffic
requiredDataConnectors:
- dataTypes:
  - Syslog
  connectorId: SymantecProxySG
- datatypes:
  - Syslog
  connectorId: SyslogAma
entityMappings:
- fieldMappings:
  - identifier: FullName
    columnName: HostCustomEntity
  entityType: Host
- fieldMappings:
  - identifier: Address
    columnName: IPCustomEntity
  entityType: IP
triggerThreshold: 0
id: 7a58b253-0ef2-4248-b4e5-c350f15a8346
tactics:
- DefenseEvasion
- CommandAndControl
version: 1.0.3
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/SymantecProxySG/Analytic Rules/ExcessiveDeniedProxyTraffic.yaml
queryPeriod: 1h
kind: Scheduled
queryFrequency: 1h
severity: Low
status: Available
description: |
    'This alert creates an incident when a client generates an excessive amounts of denied proxy traffic.'
query: |
  let threshold = 100;
  SymantecProxySG
  | where sc_filter_result =~ "DENIED"
  | summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by c_ip, cs_host
  | where count_ > threshold
  | extend timestamp = StartTime, HostCustomEntity = cs_host, IPCustomEntity = c_ip  
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/7a58b253-0ef2-4248-b4e5-c350f15a8346')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/7a58b253-0ef2-4248-b4e5-c350f15a8346')]",
      "properties": {
        "alertRuleTemplateName": "7a58b253-0ef2-4248-b4e5-c350f15a8346",
        "customDetails": null,
        "description": "'This alert creates an incident when a client generates an excessive amounts of denied proxy traffic.'\n",
        "displayName": "Excessive Denied Proxy Traffic",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "HostCustomEntity",
                "identifier": "FullName"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IPCustomEntity",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/SymantecProxySG/Analytic Rules/ExcessiveDeniedProxyTraffic.yaml",
        "query": "let threshold = 100;\nSymantecProxySG\n| where sc_filter_result =~ \"DENIED\"\n| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by c_ip, cs_host\n| where count_ > threshold\n| extend timestamp = StartTime, HostCustomEntity = cs_host, IPCustomEntity = c_ip\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "severity": "Low",
        "status": "Available",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl",
          "DefenseEvasion"
        ],
        "techniques": [
          "T1090",
          "T1562"
        ],
        "templateVersion": "1.0.3",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}