TI map IP entity to DNS Events (ASIM DNS schema)

Severity: medium
Time window: 14d
Group by: Id, ObservableValue
Source: github.com/Azure/Azure-Sentinel

'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.'

MITRE ATT&CK coverage

Tactic	Techniques
Command & Control	`T1071` Application Layer Protocol

Rule body kusto

id: b306fba8-1a28-449f-aa24-30362e16d4f5
name: 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](https://aka.ms/AboutASIM) and supports any built-in or custom source that supports the ASIM DNS schema.'
severity: Medium
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
queryFrequency: 1h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
relevantTechniques:
  - T1071
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
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
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: Dvc
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IoC
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: SrcIpAddr
customDetails:
  LatestIndicatorTime: LatestIndicatorTime
  Description: Description
  ActivityGroupNames: ActivityGroupNames
  IndicatorId: IndicatorId
  ThreatType: ThreatType
  ExpirationDateTime: ValidUntil
  ConfidenceScore: Confidence
  DNSRequestTime: imDns_mintime
  SourceIPAddress: SrcIpAddr
  DnsQuery: DnsQuery
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.
version: 1.2.10
kind: Scheduled

Stages and Predicates

Parameters

let dt_lookBack = 1h;
let ioc_lookBack = 14d;

The stages below define let IP_TI (the rule's main pipeline source).

Stage 1: `source`

ThreatIntelIndicators

Stage 2: `where`

| where TimeGenerated >= ago(ioc_lookBack)

Stage 3: `extend`

| extend IndicatorType = replace(@"\[|\]|\""", "", tostring(split(ObservableKey, ":", 0)))

Stage 4: `where`

| where IndicatorType == "ipv4-addr"

Stage 5: `extend` (4 consecutive steps)

| extend TrafficLightProtocolLevel = tostring(parse_json(AdditionalFields).TLPLevel)
| extend NetworkSourceIP = ObservableValue
| extend IoC = NetworkSourceIP
| extend IndicatorId = tostring(split(Id, "--")[2])

Stage 6: `summarize`

| summarize LatestIndicatorTime = arg_max(TimeGenerated, *) by Id, ObservableValue

Stage 7: `where`

| where IsActive and (ValidUntil > now() or isempty(ValidUntil))

The stages below run on IP_TI (the outer pipeline).

Stage 8: `project-reorder`

IP_TI
| project-reorder *, IsActive, Tags, TrafficLightProtocolLevel, NetworkSourceIP, Type, IoC

Stage 9: `join`

| join kind=innerunique
(
_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

Stage 10: `where`

| where imDns_mintime < ValidUntil

Stage 11: `extend` (3 consecutive steps)

| 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])

Stage 12: `project`

| project imDns_mintime, imDns_maxtime, Description, ActivityGroupNames, IndicatorId, ThreatType, LatestIndicatorTime, ValidUntil, Confidence, 
SrcIpAddr, IoC, Dvc, EventVendor, EventProduct, DnsQuery, DnsResponseName, Type

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`DnsResponseName`	is_not_null	(no value, null check)
`IndicatorType`	eq	`ipv4-addr` transforms: `cased`
`ValidUntil`	is_null	(no value, null check)
`imDns_mintime`	lt	`ValidUntil` transforms: `cased`

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field	Source
`ActivityGroupNames`	`project`
`Confidence`	`project`
`Description`	`project`
`DnsQuery`	`project`
`DnsResponseName`	`project`
`Dvc`	`project`
`EventProduct`	`project`
`EventVendor`	`project`
`IndicatorId`	`project`
`IoC`	`project`
`LatestIndicatorTime`	`project`
`SrcIpAddr`	`project`
`ThreatType`	`project`
`Type`	`project`
`ValidUntil`	`project`
`imDns_maxtime`	`project`
`imDns_mintime`	`project`

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`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
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`?`	Toggle this help
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`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

TI map IP entity to DNS Events (ASIM DNS schema)

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `where`

Stage 5: `extend` (4 consecutive steps)

Stage 6: `summarize`

Stage 7: `where`

Stage 8: `project-reorder`

Stage 9: `join`

Stage 10: `where`

Stage 11: `extend` (3 consecutive steps)

Stage 12: `project`

Indicators

Output fields

Keyboard shortcuts

Search operators

TI map IP entity to DNS Events (ASIM DNS schema)

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: source

Stage 2: where

Stage 3: extend

Stage 4: where

Stage 5: extend (4 consecutive steps)

Stage 6: summarize

Stage 7: where

Stage 8: project-reorder

Stage 9: join

Stage 10: where

Stage 11: extend (3 consecutive steps)

Stage 12: project

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`

Stage 4: `where`

Stage 5: `extend` (4 consecutive steps)

Stage 6: `summarize`

Stage 7: `where`

Stage 8: `project-reorder`

Stage 9: `join`

Stage 10: `where`

Stage 11: `extend` (3 consecutive steps)

Stage 12: `project`