Microsoft Sentinel Analytic Rules
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TI map Domain entity to Dns Events ASIM DNS Schema

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Id7c1ea2e6-6210-412c-92e4-180803a741b4
RulenameTI map Domain entity to Dns Events (ASIM DNS Schema)
DescriptionIdentifies 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
SeverityMedium
TacticsCommandAndControl
TechniquesT1071
Required data connectorsAzureFirewall
CiscoUmbrellaDataConnector
Corelight
DNS
GCPDNSDataConnector
InfobloxNIOS
MicrosoftDefenderThreatIntelligence
NXLogDnsLogs
ThreatIntelligence
ThreatIntelligenceTaxii
Zscaler
KindScheduled
Query frequency1h
Query period14d
Trigger threshold0
Trigger operatorgt
Source Urihttps://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence (NEW)/Analytic Rules/imDns_DomainEntity_DnsEvents.yaml
Version1.2.3
Arm template7c1ea2e6-6210-412c-92e4-180803a741b4.json
Deploy To Azure
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)))
  | extend IndicatorId = tostring(split(Id, "--")[2])
  | where IndicatorType == "domain-name"
  | extend DomainName = ObservableValue
  | extend Url = iff(ObservableKey == "url:value", ObservableValue, "")
  
  | 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 IndicatorId, ObservableValue
  | where IsActive and (ValidUntil > now() or isempty(ValidUntil));
let Domains = DomainTIs  |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, IndicatorId, 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)
relevantTechniques:
- T1071
entityMappings:
- fieldMappings:
  - columnName: Dvc
    identifier: FullName
  - columnName: HostName
    identifier: HostName
  - columnName: HostNameDomain
    identifier: DnsDomain
  entityType: Host
- fieldMappings:
  - columnName: SrcIpAddr
    identifier: Address
  entityType: IP
- fieldMappings:
  - columnName: Url
    identifier: Url
  entityType: URL
- fieldMappings:
  - columnName: Domain
    identifier: DomainName
  entityType: DNS
triggerThreshold: 0
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:
  DNSRequestTime: DNS_TimeGenerated
  ActivityGroupNames: ActivityGroupNames
  QueryType: DnsQueryType
  DnsQuery: DnsQuery
  IndicatorId: IndicatorId
  LatestIndicatorTime: LatestIndicatorTime
  ConfidenceScore: Confidence
  SourceIPAddress: SrcIpAddr
  Description: Description
  ExpirationDateTime: ValidUntil
requiredDataConnectors:
- connectorId: ThreatIntelligence
  dataTypes:
  - ThreatIntelIndicators
- connectorId: ThreatIntelligenceTaxii
  dataTypes:
  - ThreatIntelIndicators
- 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:
  - ThreatIntelIndicators
- connectorId: CiscoUmbrellaDataConnector
  dataTypes:
  - Cisco_Umbrella_dns_CL
- connectorId: Corelight
  dataTypes:
  - Corelight_CL
triggerOperator: gt
version: 1.2.3
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence (NEW)/Analytic Rules/imDns_DomainEntity_DnsEvents.yaml
id: 7c1ea2e6-6210-412c-92e4-180803a741b4
queryFrequency: 1h
query: "let HAS_ANY_MAX = 10000;\nlet dt_lookBack = 1h;\nlet ioc_lookBack = 14d;\nlet DomainTIs= ThreatIntelIndicators\n  // Picking up only IOC's that contain the entities we want\n  //extract key part of kv pair\n  | extend IndicatorType = replace(@\"\\[|\\]|\\\"\"\", \"\", tostring(split(ObservableKey, \":\", 0)))\n  | extend IndicatorId = tostring(split(Id, \"--\")[2])\n  | where IndicatorType == \"domain-name\"\n  | extend DomainName = ObservableValue\n  | extend Url = iff(ObservableKey == \"url:value\", ObservableValue, \"\")\n  \n  | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)\n  | extend ThreatList = tostring(parse_json(Data).indicator_types[0])\n  | where TimeGenerated >= ago(ioc_lookBack)\n  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by IndicatorId, ObservableValue\n  | where IsActive and (ValidUntil > now() or isempty(ValidUntil));\nlet Domains = DomainTIs  |summarize NDomains=dcount(DomainName), DomainsList=make_set(DomainName) \n  | project DomainList = iff(NDomains > HAS_ANY_MAX, dynamic([]), DomainsList);\nDomainTIs\n| project-reorder *, ThreatList, IsActive, Tags, TrafficLightProtocolLevel, DomainName, Type\n  | join (\n      _Im_Dns(starttime=ago(dt_lookBack), domain_has_any=toscalar(Domains))\n      | extend DNS_TimeGenerated = TimeGenerated\n) on $left.DomainName==$right.DnsQuery\n| where DNS_TimeGenerated < ValidUntil\n| extend Description = tostring(parse_json(Data).description)\n| extend ActivityGroupNames = extract(@\"ActivityGroup:(\\S+)\", 1, tostring(parse_json(Data).labels))\n| project LatestIndicatorTime, Description, ActivityGroupNames, IndicatorId, ValidUntil, Confidence, DNS_TimeGenerated, Dvc, SrcIpAddr, Domain, DnsQuery, DnsQueryType, Url\n| extend HostName = tostring(split(Dvc, \".\")[0]), DomainIndex = toint(indexof(Dvc, '.'))\n| extend HostNameDomain = iff(DomainIndex != -1, substring(Dvc, DomainIndex + 1), Dvc)\n"
severity: Medium
kind: Scheduled
queryPeriod: 14d
name: TI map Domain entity to Dns Events (ASIM DNS Schema)
tactics:
- CommandAndControl
tags:
- version: 1.0.0
  Id: 85aca4d1-5d15-4001-abd9-acb86ca1786a
- Schema: ASIMDns
  SchemaVersion: 0.1.1