Corelight - C2 DGA Detected Via Repetitive Failures

let threshold = 25;
Corelight
| where EventType =~ 'dns'
| where DnsResponseCodeName in~ ('NXDOMAIN', 'SERVFAIL')
| summarize count() by DnsQueryName, SrcIpAddr, bin(TimeGenerated, 5m)
| where count_ > threshold
| extend IPCustomEntity = SrcIpAddr

kind: Scheduled
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Corelight/Analytic Rules/CorelightC2RepetitiveFailures.yaml
severity: Medium
name: Corelight - C2 DGA Detected Via Repetitive Failures
entityMappings:
- entityType: IP
  fieldMappings:
  - columnName: IPCustomEntity
    identifier: Address
queryFrequency: 1h
triggerThreshold: 0
queryPeriod: 1h
description: |
    'Detects large amounts of DNS resolution failures.'
id: 8eaa2268-74ee-492c-b869-450eff707fef
version: 1.0.0
tactics:
- CommandAndControl
query: |
  let threshold = 25;
  Corelight
  | where EventType =~ 'dns'
  | where DnsResponseCodeName in~ ('NXDOMAIN', 'SERVFAIL')
  | summarize count() by DnsQueryName, SrcIpAddr, bin(TimeGenerated, 5m)
  | where count_ > threshold
  | extend IPCustomEntity = SrcIpAddr  
status: Available
requiredDataConnectors:
- dataTypes:
  - Corelight
  connectorId: Corelight
triggerOperator: gt

{
  "$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/8eaa2268-74ee-492c-b869-450eff707fef')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/8eaa2268-74ee-492c-b869-450eff707fef')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01-preview",
      "properties": {
        "displayName": "Corelight - C2 DGA Detected Via Repetitive Failures",
        "description": "'Detects large amounts of DNS resolution failures.'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "let threshold = 25;\nCorelight\n| where EventType =~ 'dns'\n| where DnsResponseCodeName in~ ('NXDOMAIN', 'SERVFAIL')\n| summarize count() by DnsQueryName, SrcIpAddr, bin(TimeGenerated, 5m)\n| where count_ > threshold\n| extend IPCustomEntity = SrcIpAddr\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl"
        ],
        "alertRuleTemplateName": "8eaa2268-74ee-492c-b869-450eff707fef",
        "customDetails": null,
        "entityMappings": [
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "identifier": "Address",
                "columnName": "IPCustomEntity"
              }
            ]
          }
        ],
        "templateVersion": "1.0.0",
        "status": "Available",
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Corelight/Analytic Rules/CorelightC2RepetitiveFailures.yaml"
      }
    }
  ]
}