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

alertDetailsOverride:
  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.
  alertDisplayNameFormat: The response {{IoC}} to DNS query matched an IoC
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.'
kind: Scheduled
tactics:
- CommandAndControl
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: CiscoUmbrellaDataConnector
  dataTypes:
  - Cisco_Umbrella_dns_CL
- connectorId: MicrosoftDefenderThreatIntelligence
  dataTypes:
  - ThreatIntelligenceIndicator
- connectorId: Corelight
  dataTypes:
  - Corelight_CL
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence/Analytic Rules/imDns_IPEntity_DnsEvents.yaml
severity: Medium
name: TI map IP entity to DNS Events (ASIM DNS schema)
customDetails:
  ThreatType: ThreatType
  ActivityGroupNames: ActivityGroupNames
  ExpirationDateTime: ExpirationDateTime
  Description: Description
  DNSRequestTime: imDns_mintime
  IndicatorId: IndicatorId
  DnsQuery: DnsQuery
  LatestIndicatorTime: LatestIndicatorTime
  ConfidenceScore: ConfidenceScore
  SourceIPAddress: SrcIpAddr
triggerThreshold: 0
queryPeriod: 14d
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  
relevantTechniques:
- T1071
id: 67775878-7f8b-4380-ac54-115e1e828901
queryFrequency: 1h
entityMappings:
- entityType: Host
  fieldMappings:
  - columnName: Dvc
    identifier: FullName
- entityType: IP
  fieldMappings:
  - columnName: IoC
    identifier: Address
- entityType: IP
  fieldMappings:
  - columnName: SrcIpAddr
    identifier: Address
triggerOperator: gt
version: 1.2.4
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

ARM