TI map IP entity to DNS Events ASIM DNS schema
| Id | b306fba8-1a28-449f-aa24-30362e16d4f5 |
| 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 (NEW)/Analytic Rules/imDns_IPEntity_DnsEvents.yaml |
| Version | 1.2.10 |
| Arm template | b306fba8-1a28-449f-aa24-30362e16d4f5.json |
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
queryPeriod: 14d
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
name: TI map IP entity to DNS Events (ASIM DNS schema)
entityMappings:
- fieldMappings:
- columnName: Dvc
identifier: FullName
entityType: Host
- fieldMappings:
- columnName: IoC
identifier: Address
entityType: IP
- fieldMappings:
- columnName: SrcIpAddr
identifier: Address
entityType: IP
OriginalUri: https://github.com/Azure/Azure-Sentinel/blob/master/Solutions/Threat Intelligence (NEW)/Analytic Rules/imDns_IPEntity_DnsEvents.yaml
tags:
- ParentAlert: https://github.com/Azure/Azure-Sentinel/blob/master/Detections/ThreatIntelligenceIndicator/IPEntity_DnsEvents.yaml
version: 1.0.0
- SchemaVersion: 0.1.1
Schema: ASIMDns
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
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
version: 1.2.10
alertDetailsOverride:
alertDisplayNameFormat: The response {{IoC}} to DNS query matched an IoC
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.
queryFrequency: 1h
severity: Medium
relevantTechniques:
- T1071
triggerOperator: gt
triggerThreshold: 0
customDetails:
Description: Description
SourceIPAddress: SrcIpAddr
IndicatorId: IndicatorId
LatestIndicatorTime: LatestIndicatorTime
DNSRequestTime: imDns_mintime
ThreatType: ThreatType
ExpirationDateTime: ValidUntil
ConfidenceScore: Confidence
ActivityGroupNames: ActivityGroupNames
DnsQuery: DnsQuery
tactics:
- CommandAndControl
id: b306fba8-1a28-449f-aa24-30362e16d4f5