TI Map IP entity to DNS Events ASIM DNS schema | Microsoft Sentinel Analytic Rules

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Id	b306fba8-1a28-449f-aa24-30362e16d4f5
Rulename	TI Map IP entity to DNS Events (ASIM DNS schema)
Description	This rule identifies DNS requests for which response IP address is a known IoC. This analytic rule uses ASIM and supports any built-in or custom source that supports the ASIM DNS schema.
Severity	Medium
Tactics	CommandAndControl
Techniques	T1071
Required data connectors	AzureFirewall CiscoUmbrellaDataConnector Corelight DNS GCPDNSDataConnector InfobloxNIOS MicrosoftDefenderThreatIntelligence NXLogDnsLogs ThreatIntelligence ThreatIntelligenceTaxii Zscaler
Kind	Scheduled
Query frequency	1h
Query period	14d
Trigger threshold	0
Trigger operator	gt
Source Uri	https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat%20Intelligence%20%28NEW%29/Analytic%20Rules/imDns_IPEntity_DnsEvents.yaml
Version	1.2.11
Arm template	b306fba8-1a28-449f-aa24-30362e16d4f5.json

KQL

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let IP_TI = 
ThreatIntelIndicators
| where TimeGenerated >= ago(ioc_lookBack)
//extract key part of kv pair
| extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
| where IndicatorType == "ipv4-addr"
| extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
| extend NetworkSourceIP = ObservableValue
| extend IoC = NetworkSourceIP
| extend IndicatorId = tostring(split(Id, "--")[2])
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
| where IsActive and (ValidUntil > now() or isempty(ValidUntil));
IP_TI
 | project-reorder *, IsActive, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, IoC
| join kind=innerunique // using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated
(
_Im_Dns(starttime=ago(dt_lookBack))
| where isnotempty(DnsResponseName)
| summarize imDns_mintime=min(TimeGenerated), imDns_maxtime=max(TimeGenerated) by SrcIpAddr, DnsQuery, DnsResponseName, Dvc, EventProduct, EventVendor
| extend addresses = extract_all (@'(\d+\.\d+\.\d+\.\d+)', DnsResponseName)
| mv-expand IoC = addresses to typeof(string)
)
on IoC
| where imDns_mintime < ValidUntil
| extend Description = tostring(parse_json(Data).description)
| extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
| extend ThreatType = tostring(Data.indicator_types[0])
| project imDns_mintime, imDns_maxtime, Description, ActivityGroupNames, IndicatorId, ThreatType, LatestIndicatorTime, ValidUntil, Confidence, 
SrcIpAddr, IoC, Dvc, EventVendor, EventProduct, DnsQuery, DnsResponseName, Type

YAML

queryFrequency: 1h
alertDetailsOverride:
  alertDisplayNameFormat: The response {{IoC}} to DNS query matched an IoC
  alertDescriptionFormat: The response address {{IoC}} to a DNS query matched a known indicator of compromise of {{ThreatType}}. Consult the threat intelligence blade for more information on the indicator.
triggerThreshold: 0
tactics:
- CommandAndControl
kind: Scheduled
name: TI Map IP entity to DNS Events (ASIM DNS schema)
description: |
  'This rule identifies DNS requests for which response IP address is a known IoC. This analytic rule uses [ASIM](https://aka.ms/AboutASIM) and supports any built-in or custom source that supports the ASIM DNS schema.'
customDetails:
  DNSRequestTime: imDns_mintime
  SourceIPAddress: SrcIpAddr
  Description: Description
  ConfidenceScore: Confidence
  IndicatorId: IndicatorId
  LatestIndicatorTime: LatestIndicatorTime
  ExpirationDateTime: ValidUntil
  DnsQuery: DnsQuery
  ThreatType: ThreatType
  ActivityGroupNames: ActivityGroupNames
version: 1.2.11
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat%20Intelligence%20%28NEW%29/Analytic%20Rules/imDns_IPEntity_DnsEvents.yaml
relevantTechniques:
- T1071
requiredDataConnectors:
- dataTypes:
  - ThreatIntelIndicators
  connectorId: ThreatIntelligence
- dataTypes:
  - ThreatIntelIndicators
  connectorId: ThreatIntelligenceTaxii
- dataTypes:
  - DnsEvents
  connectorId: DNS
- dataTypes:
  - AzureDiagnostics
  connectorId: AzureFirewall
- dataTypes:
  - CommonSecurityLog
  connectorId: Zscaler
- dataTypes:
  - Syslog
  connectorId: InfobloxNIOS
- dataTypes:
  - GCP_DNS_CL
  connectorId: GCPDNSDataConnector
- dataTypes:
  - NXLog_DNS_Server_CL
  connectorId: NXLogDnsLogs
- dataTypes:
  - Cisco_Umbrella_dns_CL
  connectorId: CiscoUmbrellaDataConnector
- dataTypes:
  - ThreatIntelIndicators
  connectorId: MicrosoftDefenderThreatIntelligence
- dataTypes:
  - Corelight_CL
  connectorId: Corelight
severity: Medium
triggerOperator: gt
entityMappings:
- entityType: Host
  fieldMappings:
  - columnName: Dvc
    identifier: FullName
- entityType: IP
  fieldMappings:
  - columnName: IoC
    identifier: Address
- entityType: IP
  fieldMappings:
  - columnName: SrcIpAddr
    identifier: Address
tags:
- ParentAlert: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/ThreatIntelligenceIndicator/IPEntity_DnsEvents.yaml
  version: 1.0.0
- Schema: ASIMDns
  SchemaVersion: 0.1.1
queryPeriod: 14d
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let IP_TI = 
  ThreatIntelIndicators
  | where TimeGenerated >= ago(ioc_lookBack)
  //extract key part of kv pair
  | extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
  | where IndicatorType == "ipv4-addr"
  | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
  | extend NetworkSourceIP = ObservableValue
  | extend IoC = NetworkSourceIP
  | extend IndicatorId = tostring(split(Id, "--")[2])
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
  | where IsActive and (ValidUntil > now() or isempty(ValidUntil));
  IP_TI
   | project-reorder *, IsActive, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, IoC
  | join kind=innerunique // using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated
  (
  _Im_Dns(starttime=ago(dt_lookBack))
  | where isnotempty(DnsResponseName)
  | summarize imDns_mintime=min(TimeGenerated), imDns_maxtime=max(TimeGenerated) by SrcIpAddr, DnsQuery, DnsResponseName, Dvc, EventProduct, EventVendor
  | extend addresses = extract_all (@'(\d+\.\d+\.\d+\.\d+)', DnsResponseName)
  | mv-expand IoC = addresses to typeof(string)
  )
  on IoC
  | where imDns_mintime < ValidUntil
  | extend Description = tostring(parse_json(Data).description)
  | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
  | extend ThreatType = tostring(Data.indicator_types[0])
  | project imDns_mintime, imDns_maxtime, Description, ActivityGroupNames, IndicatorId, ThreatType, LatestIndicatorTime, ValidUntil, Confidence, 
  SrcIpAddr, IoC, Dvc, EventVendor, EventProduct, DnsQuery, DnsResponseName, Type
id: b306fba8-1a28-449f-aa24-30362e16d4f5

ARM

{
  "$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/b306fba8-1a28-449f-aa24-30362e16d4f5')]",
      "kind": "Scheduled",
      "name": "[concat(parameters('workspace'),'/Microsoft.SecurityInsights/b306fba8-1a28-449f-aa24-30362e16d4f5')]",
      "properties": {
        "alertDetailsOverride": {
          "alertDescriptionFormat": "The response address {{IoC}} to a DNS query matched a known indicator of compromise of {{ThreatType}}. Consult the threat intelligence blade for more information on the indicator.",
          "alertDisplayNameFormat": "The response {{IoC}} to DNS query matched an IoC"
        },
        "alertRuleTemplateName": "b306fba8-1a28-449f-aa24-30362e16d4f5",
        "customDetails": {
          "ActivityGroupNames": "ActivityGroupNames",
          "ConfidenceScore": "Confidence",
          "Description": "Description",
          "DnsQuery": "DnsQuery",
          "DNSRequestTime": "imDns_mintime",
          "ExpirationDateTime": "ValidUntil",
          "IndicatorId": "IndicatorId",
          "LatestIndicatorTime": "LatestIndicatorTime",
          "SourceIPAddress": "SrcIpAddr",
          "ThreatType": "ThreatType"
        },
        "description": "'This rule identifies DNS requests for which response IP address is a known IoC. This analytic rule uses [ASIM](https://aka.ms/AboutASIM) and supports any built-in or custom source that supports the ASIM DNS schema.'\n",
        "displayName": "TI Map IP entity to DNS Events (ASIM DNS schema)",
        "enabled": true,
        "entityMappings": [
          {
            "entityType": "Host",
            "fieldMappings": [
              {
                "columnName": "Dvc",
                "identifier": "FullName"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "IoC",
                "identifier": "Address"
              }
            ]
          },
          {
            "entityType": "IP",
            "fieldMappings": [
              {
                "columnName": "SrcIpAddr",
                "identifier": "Address"
              }
            ]
          }
        ],
        "OriginalUri": "https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat%20Intelligence%20%28NEW%29/Analytic%20Rules/imDns_IPEntity_DnsEvents.yaml",
        "query": "let dt_lookBack = 1h;\nlet ioc_lookBack = 14d;\nlet IP_TI = \nThreatIntelIndicators\n| where TimeGenerated >= ago(ioc_lookBack)\n//extract key part of kv pair\n| extend IndicatorType = replace(@\"\\[|\\]|\\\"\"\", \"\", tostring(split(ObservableKey, \":\", 0)))\n| where IndicatorType == \"ipv4-addr\"\n| extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)\n| extend NetworkSourceIP = ObservableValue\n| extend IoC = NetworkSourceIP\n| extend IndicatorId = tostring(split(Id, \"--\")[2])\n| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue\n| where IsActive and (ValidUntil > now() or isempty(ValidUntil));\nIP_TI\n | project-reorder *, IsActive, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, IoC\n| join kind=innerunique // using innerunique to keep perf fast and result set low, we only need one match to indicate potential malicious activity that needs to be investigated\n(\n_Im_Dns(starttime=ago(dt_lookBack))\n| where isnotempty(DnsResponseName)\n| summarize imDns_mintime=min(TimeGenerated), imDns_maxtime=max(TimeGenerated) by SrcIpAddr, DnsQuery, DnsResponseName, Dvc, EventProduct, EventVendor\n| extend addresses = extract_all (@'(\\d+\\.\\d+\\.\\d+\\.\\d+)', DnsResponseName)\n| mv-expand IoC = addresses to typeof(string)\n)\non IoC\n| where imDns_mintime < ValidUntil\n| extend Description = tostring(parse_json(Data).description)\n| extend ActivityGroupNames = extract(@\"ActivityGroup:(\\S+)\", 1, tostring(parse_json(Data).labels))\n| extend ThreatType = tostring(Data.indicator_types[0])\n| project imDns_mintime, imDns_maxtime, Description, ActivityGroupNames, IndicatorId, ThreatType, LatestIndicatorTime, ValidUntil, Confidence, \nSrcIpAddr, IoC, Dvc, EventVendor, EventProduct, DnsQuery, DnsResponseName, Type\n",
        "queryFrequency": "PT1H",
        "queryPeriod": "P14D",
        "severity": "Medium",
        "subTechniques": [],
        "suppressionDuration": "PT1H",
        "suppressionEnabled": false,
        "tactics": [
          "CommandAndControl"
        ],
        "tags": [
          {
            "ParentAlert": "https://github.com/Azure/Azure-Sentinel/blob/master/Detections/ThreatIntelligenceIndicator/IPEntity_DnsEvents.yaml",
            "version": "1.0.0"
          },
          {
            "Schema": "ASIMDns",
            "SchemaVersion": "0.1.1"
          }
        ],
        "techniques": [
          "T1071"
        ],
        "templateVersion": "1.2.11",
        "triggerOperator": "GreaterThan",
        "triggerThreshold": 0
      },
      "type": "Microsoft.OperationalInsights/workspaces/providers/alertRules"
    }
  ]
}