Solutions/Threat Intelligence (NEW)/Analytic Rules/imDns_DomainEntity_DnsEvents.yaml

id: 7c1ea2e6-6210-412c-92e4-180803a741b4
name: 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](https://aka.ms/AboutASIM) and supports any built-in or custom source that supports the ASIM DNS schema'
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
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
relevantTechniques:
  - T1071
tags:
  - Id: 85aca4d1-5d15-4001-abd9-acb86ca1786a
    version: 1.0.0
  - Schema: ASIMDns
    SchemaVersion: 0.1.1
query: |
  let HAS_ANY_MAX = 10000;
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let DomainTIs= ThreatIntelIndicators
    // Picking up only IOC's that contain the entities we want
    //extract key part of kv pair
    | extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
    | where isnotempty(IndicatorType) and IndicatorType == "domain-name"
    | extend DomainName = ObservableValue
    | extend Url = iff(ObservableKey == "url:value", ObservableValue, "")
    | where isnotempty(DomainName)
    | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
    | extend ThreatList = tostring(parse_json(Data).indicator_types[0])
    | where TimeGenerated >= ago(ioc_lookBack)
    | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id
    | where IsActive == true and ValidUntil > 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
  | project-reorder *, ThreatList, IsActive, Tags, TrafficLightProtocolLevel, DomainName, Type
    | join (
        _Im_Dns(starttime=ago(dt_lookBack), domain_has_any=toscalar(Domains))
        | extend DNS_TimeGenerated = TimeGenerated
  ) on $left.DomainName==$right.DnsQuery
  | where DNS_TimeGenerated < ValidUntil
  | extend Description = tostring(parse_json(Data).description)
  | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
  | project LatestIndicatorTime, Description, ActivityGroupNames, Id, ValidUntil, Confidence, DNS_TimeGenerated, Dvc, SrcIpAddr, Domain, DnsQuery, DnsQueryType, Url
  | extend HostName = tostring(split(Dvc, ".")[0]), DomainIndex = toint(indexof(Dvc, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(Dvc, DomainIndex + 1), Dvc)
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        
customDetails:
  LatestIndicatorTime: LatestIndicatorTime
  Description: Description
  ActivityGroupNames: ActivityGroupNames
  IndicatorId: IndicatorId
  ThreatType: ThreatType
  ExpirationDateTime: ExpirationDateTime
  ConfidenceScore: Confidence
  DNSRequestTime: DNS_TimeGenerated
  SourceIPAddress: SrcIpAddr
  DnsQuery: DnsQuery
  QueryType: DnsQueryType
version: 1.2.0
kind: Scheduled