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

queryPeriod: 14d
kind: Scheduled
entityMappings:
- entityType: Host
  fieldMappings:
  - identifier: FullName
    columnName: Dvc
  - identifier: HostName
    columnName: HostName
  - identifier: DnsDomain
    columnName: HostNameDomain
- entityType: IP
  fieldMappings:
  - identifier: Address
    columnName: SrcIpAddr
- entityType: URL
  fieldMappings:
  - identifier: Url
    columnName: Url
- entityType: DNS
  fieldMappings:
  - identifier: DomainName
    columnName: Domain
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
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'  
queryFrequency: 1h
triggerOperator: gt
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)  
name: TI map Domain entity to Dns Events (ASIM DNS Schema)
id: 999e9f5d-db4a-4b07-a206-29c4e667b7e8
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/imDns_DomainEntity_DnsEvents.yaml
severity: Medium
version: 1.1.8
relevantTechniques:
- T1071
tags:
- version: 1.0.0
  Id: 85aca4d1-5d15-4001-abd9-acb86ca1786a
- Schema: ASIMDns
  SchemaVersion: 0.1.1
triggerThreshold: 0
customDetails:
  Description: Description
  IndicatorId: IndicatorId
  ActivityGroupNames: ActivityGroupNames
  DnsQuery: DnsQuery
  SourceIPAddress: SrcIpAddr
  QueryType: DnsQueryType
  ExpirationDateTime: ExpirationDateTime
  ThreatType: ThreatType
  LatestIndicatorTime: LatestIndicatorTime
  DNSRequestTime: DNS_TimeGenerated
  ConfidenceScore: ConfidenceScore
tactics:
- CommandAndControl

ARM