TI map Domain entity to Dns Events ASIM DNS Schema

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Id	999e9f5d-db4a-4b07-a206-29c4e667b7e8
Rulename	TI map Domain entity to Dns Events (ASIM DNS Schema)
Description	Identifies a match in DNS events from any Domain IOC from TI 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_DomainEntity_DnsEvents.yaml
Version	1.1.8
Arm template	999e9f5d-db4a-4b07-a206-29c4e667b7e8.json

KQL

let HAS_ANY_MAX = 10000;
let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let DomainTIs= ThreatIntelligenceIndicator
  // Picking up only IOC's that contain the entities we want
  | where isnotempty(DomainName)
  | where TimeGenerated >= ago(ioc_lookBack)
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
  | where Active == true and ExpirationDateTime > now();
let Domains = DomainTIs | where isnotempty(DomainName) |summarize NDomains=dcount(DomainName), DomainsList=make_set(DomainName) 
  | project DomainList = iff(NDomains > HAS_ANY_MAX, dynamic([]), DomainsList) ;
DomainTIs
  | join (
      _Im_Dns(starttime=ago(dt_lookBack), domain_has_any=toscalar(Domains))
      | extend DNS_TimeGenerated = TimeGenerated
) on $left.DomainName==$right.DnsQuery
| where DNS_TimeGenerated < ExpirationDateTime
| project LatestIndicatorTime, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, Url, DNS_TimeGenerated, Dvc, SrcIpAddr, Domain, DnsQuery, DnsQueryType
| extend HostName = tostring(split(Dvc, ".")[0]), DomainIndex = toint(indexof(Dvc, '.'))
| extend HostNameDomain = iff(DomainIndex != -1, substring(Dvc, DomainIndex + 1), Dvc)

YAML

name: TI map Domain entity to Dns Events (ASIM DNS Schema)
query: |
  let HAS_ANY_MAX = 10000;
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let DomainTIs= ThreatIntelligenceIndicator
    // Picking up only IOC's that contain the entities we want
    | where isnotempty(DomainName)
    | where TimeGenerated >= ago(ioc_lookBack)
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId
    | where Active == true and ExpirationDateTime > now();
  let Domains = DomainTIs | where isnotempty(DomainName) |summarize NDomains=dcount(DomainName), DomainsList=make_set(DomainName) 
    | project DomainList = iff(NDomains > HAS_ANY_MAX, dynamic([]), DomainsList) ;
  DomainTIs
    | join (
        _Im_Dns(starttime=ago(dt_lookBack), domain_has_any=toscalar(Domains))
        | extend DNS_TimeGenerated = TimeGenerated
  ) on $left.DomainName==$right.DnsQuery
  | where DNS_TimeGenerated < ExpirationDateTime
  | project LatestIndicatorTime, Description, ActivityGroupNames, IndicatorId, ThreatType, ExpirationDateTime, ConfidenceScore, Url, DNS_TimeGenerated, Dvc, SrcIpAddr, Domain, DnsQuery, DnsQueryType
  | extend HostName = tostring(split(Dvc, ".")[0]), DomainIndex = toint(indexof(Dvc, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(Dvc, DomainIndex + 1), Dvc)  
entityMappings:
- entityType: Host
  fieldMappings:
  - columnName: Dvc
    identifier: FullName
  - columnName: HostName
    identifier: HostName
  - columnName: HostNameDomain
    identifier: DnsDomain
- entityType: IP
  fieldMappings:
  - columnName: SrcIpAddr
    identifier: Address
- entityType: URL
  fieldMappings:
  - columnName: Url
    identifier: Url
- entityType: DNS
  fieldMappings:
  - columnName: Domain
    identifier: DomainName
queryPeriod: 14d
tactics:
- CommandAndControl
triggerOperator: gt
kind: Scheduled
triggerThreshold: 0
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/imDns_DomainEntity_DnsEvents.yaml
relevantTechniques:
- T1071
id: 999e9f5d-db4a-4b07-a206-29c4e667b7e8
tags:
- Id: 85aca4d1-5d15-4001-abd9-acb86ca1786a
  version: 1.0.0
- Schema: ASIMDns
  SchemaVersion: 0.1.1
severity: Medium
requiredDataConnectors:
- connectorId: ThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: ThreatIntelligenceTaxii
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: DNS
  dataTypes:
  - DnsEvents
- connectorId: AzureFirewall
  dataTypes:
  - AzureDiagnostics
- connectorId: Zscaler
  dataTypes:
  - CommonSecurityLog
- connectorId: InfobloxNIOS
  dataTypes:
  - Syslog
- connectorId: GCPDNSDataConnector
  dataTypes:
  - GCP_DNS_CL
- connectorId: NXLogDnsLogs
  dataTypes:
  - NXLog_DNS_Server_CL
- connectorId: MicrosoftDefenderThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: CiscoUmbrellaDataConnector
  dataTypes:
  - Cisco_Umbrella_dns_CL
- connectorId: Corelight
  dataTypes:
  - Corelight_CL
version: 1.1.8
description: |
  Identifies a match in DNS events from any Domain IOC from TI
  This analytic rule uses [ASIM](https://aka.ms/AboutASIM) and supports any built-in or custom source that supports the ASIM DNS schema'  
customDetails:
  LatestIndicatorTime: LatestIndicatorTime
  Description: Description
  ThreatType: ThreatType
  ConfidenceScore: ConfidenceScore
  ExpirationDateTime: ExpirationDateTime
  SourceIPAddress: SrcIpAddr
  DNSRequestTime: DNS_TimeGenerated
  ActivityGroupNames: ActivityGroupNames
  QueryType: DnsQueryType
  IndicatorId: IndicatorId
  DnsQuery: DnsQuery
queryFrequency: 1h

ARM