Detect DNS queries reporting multiple errors from different clients - Static threshold based (ASIM DNS Solution)

let lookback=1h;
let threshold = 2;
let errors = dynamic(['NXDOMAIN', 'SERVFAIL', 'REFUSED']);
_Im_Dns(starttime=ago(lookback))
  | where EventResultDetails has_any (errors)
  | summarize SrcIPs = make_set(SrcIpAddr, 100) by DnsQuery, bin(TimeGenerated, 10min)
  | where array_length(SrcIPs) >= threshold
  | extend TotalIPs = array_length(SrcIPs),IPCountthreshold = threshold

eventGroupingSettings:
  aggregationKind: AlertPerResult
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/DNS Essentials/Analytic Rules/MultipleErrorsReportedForSameDNSQueryStaticThresholdBased.yaml
severity: Medium
tags:
- SchemaVersion: 0.1.6
  Schema: ASimDns
name: Detect DNS queries reporting multiple errors from different clients - Static threshold based (ASIM DNS Solution)
entityMappings:
- entityType: DNS
  fieldMappings:
  - columnName: DnsQuery
    identifier: DomainName
relevantTechniques:
- T1568
- T1573
- T1008
queryFrequency: 1h
triggerThreshold: 0
queryPeriod: 1h
description: |
    'This rule creates an alert when multiple clients report errors for the same DNS query. This helps in identifying possible similar C2 communications originating from different clients. It utilizes [ASIM](https://aka.ms/AboutASIM) normalization and is applied to any source that supports the ASIM DNS schema.'
id: 5b8344eb-fa28-4ac3-bcff-bc19d5d63089
alertDetailsOverride:
  alertDescriptionFormat: |-
    Multiple errors were detected on different clients for the same DNS query. These unsuccessful responses can be an indication of C2 communication. 

    Threshold for total clients reporting errors: '{{IPCountthreshold}}'

    Current count of clients reporting errors for this DNS query: '{{TotalIPs}}'

    Clients requesting this DNSQuery include:

    '{{SrcIPs}}'    
  alertDisplayNameFormat: "[Static threshold] Multiple errors for the same DNS query has been detected - '{{DnsQuery}}'"
customDetails:
  TotalIPs: TotalIPs
  SrcIPs: SrcIPs
  IPCountthreshold: IPCountthreshold
version: 1.0.2
tactics:
- CommandAndControl
query: |
  let lookback=1h;
  let threshold = 2;
  let errors = dynamic(['NXDOMAIN', 'SERVFAIL', 'REFUSED']);
  _Im_Dns(starttime=ago(lookback))
    | where EventResultDetails has_any (errors)
    | summarize SrcIPs = make_set(SrcIpAddr, 100) by DnsQuery, bin(TimeGenerated, 10min)
    | where array_length(SrcIPs) >= threshold
    | extend TotalIPs = array_length(SrcIPs),IPCountthreshold = threshold  
status: Available
kind: Scheduled
requiredDataConnectors: []
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/5b8344eb-fa28-4ac3-bcff-bc19d5d63089')]",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/5b8344eb-fa28-4ac3-bcff-bc19d5d63089')]",
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules",
      "kind": "Scheduled",
      "apiVersion": "2022-11-01-preview",
      "properties": {
        "displayName": "Detect DNS queries reporting multiple errors from different clients - Static threshold based (ASIM DNS Solution)",
        "description": "'This rule creates an alert when multiple clients report errors for the same DNS query. This helps in identifying possible similar C2 communications originating from different clients. It utilizes [ASIM](https://aka.ms/AboutASIM) normalization and is applied to any source that supports the ASIM DNS schema.'\n",
        "severity": "Medium",
        "enabled": true,
        "query": "let lookback=1h;\nlet threshold = 2;\nlet errors = dynamic(['NXDOMAIN', 'SERVFAIL', 'REFUSED']);\n_Im_Dns(starttime=ago(lookback))\n  | where EventResultDetails has_any (errors)\n  | summarize SrcIPs = make_set(SrcIpAddr, 100) by DnsQuery, bin(TimeGenerated, 10min)\n  | where array_length(SrcIPs) >= threshold\n  | extend TotalIPs = array_length(SrcIPs),IPCountthreshold = threshold\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "PT1H",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0,
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl"
        ],
        "techniques": [
          "T1568",
          "T1573",
          "T1008"
        ],
        "alertRuleTemplateName": "5b8344eb-fa28-4ac3-bcff-bc19d5d63089",
        "eventGroupingSettings": {
          "aggregationKind": "AlertPerResult"
        },
        "alertDetailsOverride": {
          "alertDisplayNameFormat": "[Static threshold] Multiple errors for the same DNS query has been detected - '{{DnsQuery}}'",
          "alertDescriptionFormat": "Multiple errors were detected on different clients for the same DNS query. These unsuccessful responses can be an indication of C2 communication. \n\nThreshold for total clients reporting errors: '{{IPCountthreshold}}'\n\nCurrent count of clients reporting errors for this DNS query: '{{TotalIPs}}'\n\nClients requesting this DNSQuery include:\n\n'{{SrcIPs}}'"
        },
        "customDetails": {
          "TotalIPs": "TotalIPs",
          "SrcIPs": "SrcIPs",
          "IPCountthreshold": "IPCountthreshold"
        },
        "entityMappings": [
          {
            "entityType": "DNS",
            "fieldMappings": [
              {
                "identifier": "DomainName",
                "columnName": "DnsQuery"
              }
            ]
          }
        ],
        "templateVersion": "1.0.2",
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/DNS Essentials/Analytic Rules/MultipleErrorsReportedForSameDNSQueryStaticThresholdBased.yaml",
        "status": "Available",
        "tags": [
          {
            "Schema": "ASimDns",
            "SchemaVersion": "0.1.6"
          }
        ]
      }
    }
  ]
}