Microsoft Sentinel Analytic Rules
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TI map IP entity to DNS Events ASIM DNS schema

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Idb306fba8-1a28-449f-aa24-30362e16d4f5
RulenameTI map IP entity to DNS Events (ASIM DNS schema)
DescriptionThis 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.
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_IPEntity_DnsEvents.yaml
Version1.2.10
Arm templateb306fba8-1a28-449f-aa24-30362e16d4f5.json
Deploy To Azure
let dt_lookBack = 1h;
let ioc_lookBack = 14d;
let IP_TI = 
ThreatIntelIndicators
| where TimeGenerated >= ago(ioc_lookBack)
//extract key part of kv pair
| extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
| where IndicatorType == "ipv4-addr"
| extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
| extend NetworkSourceIP = ObservableValue
| extend IoC = NetworkSourceIP
| extend IndicatorId = tostring(split(Id, "--")[2])
| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
| where IsActive and (ValidUntil > now() or isempty(ValidUntil));
IP_TI
 | project-reorder *, IsActive, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, IoC
| 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 < ValidUntil
| extend Description = tostring(parse_json(Data).description)
| extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
| extend ThreatType = tostring(Data.indicator_types[0])
| project imDns_mintime, imDns_maxtime, Description, ActivityGroupNames, IndicatorId, ThreatType, LatestIndicatorTime, ValidUntil, Confidence, 
SrcIpAddr, IoC, Dvc, EventVendor, EventProduct, DnsQuery, DnsResponseName, Type
severity: Medium
customDetails:
  LatestIndicatorTime: LatestIndicatorTime
  ExpirationDateTime: ValidUntil
  ConfidenceScore: Confidence
  IndicatorId: IndicatorId
  Description: Description
  DNSRequestTime: imDns_mintime
  ThreatType: ThreatType
  DnsQuery: DnsQuery
  SourceIPAddress: SrcIpAddr
  ActivityGroupNames: ActivityGroupNames
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence (NEW)/Analytic Rules/imDns_IPEntity_DnsEvents.yaml
queryPeriod: 14d
version: 1.2.10
tactics:
- CommandAndControl
triggerOperator: gt
queryFrequency: 1h
name: TI map IP entity to DNS Events (ASIM DNS schema)
id: b306fba8-1a28-449f-aa24-30362e16d4f5
entityMappings:
- entityType: Host
  fieldMappings:
  - columnName: Dvc
    identifier: FullName
- entityType: IP
  fieldMappings:
  - columnName: IoC
    identifier: Address
- entityType: IP
  fieldMappings:
  - columnName: SrcIpAddr
    identifier: Address
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
relevantTechniques:
- T1071
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: CiscoUmbrellaDataConnector
  dataTypes:
  - Cisco_Umbrella_dns_CL
- connectorId: MicrosoftDefenderThreatIntelligence
  dataTypes:
  - ThreatIntelIndicators
- connectorId: Corelight
  dataTypes:
  - Corelight_CL
kind: Scheduled
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.'
triggerThreshold: 0
tags:
- version: 1.0.0
  ParentAlert: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/ThreatIntelligenceIndicator/IPEntity_DnsEvents.yaml
- SchemaVersion: 0.1.1
  Schema: ASIMDns
query: |
  let dt_lookBack = 1h;
  let ioc_lookBack = 14d;
  let IP_TI = 
  ThreatIntelIndicators
  | where TimeGenerated >= ago(ioc_lookBack)
  //extract key part of kv pair
  | extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))
  | where IndicatorType == "ipv4-addr"
  | extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
  | extend NetworkSourceIP = ObservableValue
  | extend IoC = NetworkSourceIP
  | extend IndicatorId = tostring(split(Id, "--")[2])
  | summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue
  | where IsActive and (ValidUntil > now() or isempty(ValidUntil));
  IP_TI
   | project-reorder *, IsActive, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, IoC
  | 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 < ValidUntil
  | extend Description = tostring(parse_json(Data).description)
  | extend ActivityGroupNames = extract(@"ActivityGroup:(\S+)", 1, tostring(parse_json(Data).labels))
  | extend ThreatType = tostring(Data.indicator_types[0])
  | project imDns_mintime, imDns_maxtime, Description, ActivityGroupNames, IndicatorId, ThreatType, LatestIndicatorTime, ValidUntil, Confidence, 
  SrcIpAddr, IoC, Dvc, EventVendor, EventProduct, DnsQuery, DnsResponseName, Type