TI map IP entity to DNS Events ASIM DNS schema

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Id	67775878-7f8b-4380-ac54-115e1e828901
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 Intelligence/Analytic Rules/imDns_IPEntity_DnsEvents.yaml
Version	1.2.4
Arm template	67775878-7f8b-4380-ac54-115e1e828901.json

KQL

let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let IP_TI = 
ThreatIntelligenceIndicator
| where TimeGenerated >= ago(ioc_lookBack)
| extend IoC = coalesce(NetworkIP, NetworkDestinationIP, NetworkSourceIP,EmailSourceIpAddress,"NO_IP")
| where IoC != "NO_IP"
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
| where Active == true and ExpirationDateTime > now();
IP_TI
| 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 < ExpirationDateTime
| project imDns_mintime, imDns_maxtime, Description, ActivityGroupNames, IndicatorId, ThreatType, LatestIndicatorTime, ExpirationDateTime, ConfidenceScore, SrcIpAddr, IoC, Dvc, EventVendor, EventProduct, DnsQuery, DnsResponseName

YAML

triggerThreshold: 0
entityMappings:
- entityType: Host
  fieldMappings:
  - identifier: FullName
    columnName: Dvc
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: IoC
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: SrcIpAddr
requiredDataConnectors:
- dataTypes:
  - ThreatIntelligenceIndicator
  connectorId: ThreatIntelligence
- dataTypes:
  - ThreatIntelligenceIndicator
  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:
  - ThreatIntelligenceIndicator
  connectorId: MicrosoftDefenderThreatIntelligence
- dataTypes:
  - Corelight_CL
  connectorId: Corelight
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/imDns_IPEntity_DnsEvents.yaml
customDetails:
  ConfidenceScore: ConfidenceScore
  ThreatType: ThreatType
  DNSRequestTime: imDns_mintime
  SourceIPAddress: SrcIpAddr
  DnsQuery: DnsQuery
  Description: Description
  ExpirationDateTime: ExpirationDateTime
  LatestIndicatorTime: LatestIndicatorTime
  ActivityGroupNames: ActivityGroupNames
  IndicatorId: IndicatorId
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
name: TI map IP entity to DNS Events (ASIM DNS schema)
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.
relevantTechniques:
- T1071
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let IP_TI = 
  ThreatIntelligenceIndicator
  | where TimeGenerated >= ago(ioc_lookBack)
  | extend IoC = coalesce(NetworkIP, NetworkDestinationIP, NetworkSourceIP,EmailSourceIpAddress,"NO_IP")
  | where IoC != "NO_IP"
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true and ExpirationDateTime > now();
  IP_TI
  | 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 < ExpirationDateTime
  | project imDns_mintime, imDns_maxtime, Description, ActivityGroupNames, IndicatorId, ThreatType, LatestIndicatorTime, ExpirationDateTime, ConfidenceScore, SrcIpAddr, IoC, Dvc, EventVendor, EventProduct, DnsQuery, DnsResponseName  
version: 1.2.4
queryPeriod: 14d
kind: Scheduled
id: 67775878-7f8b-4380-ac54-115e1e828901
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.'
queryFrequency: 1h
severity: Medium
triggerOperator: gt
tactics:
- CommandAndControl

ARM