Detection rules › Kusto

Google DNS - Request to dynamic DNS service

Severity
medium
Time window
1h
Source
github.com/Azure/Azure-Sentinel

'Detects requests to ip lookup resources.'

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1095 Non-Application Layer Protocol

Rule body kusto

id: 09fc03e0-daec-4b22-8afa-4bba30d7e909
name: Google DNS - Request to dynamic DNS service
description: |
  'Detects requests to ip lookup resources.'
severity: Medium
requiredDataConnectors:
  - connectorId: GCPDNSDataConnector
    dataTypes:
      - GCPCloudDNS
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
relevantTechniques:
  - T1095
query: |
  let dyndns = dynamic(['noip.com', 'dynu.com', 'dyn.com', 'dynv6.com']);
  GCPCloudDNS
  | where Query in~ (dyndns)
  | extend DNSCustomEntity = Query, IPCustomEntity = SrcIpAddr
entityMappings:
  - entityType: DNS
    fieldMappings:
      - identifier: DomainName
        columnName: DNSCustomEntity
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
version: 1.0.0
kind: Scheduled

Stages and Predicates

Parameters

let dyndns = dynamic(['noip.com', 'dynu.com', 'dyn.com', 'dynv6.com']);

Stage 1: source

GCPCloudDNS

Stage 2: where

| where Query in~ (dyndns)

Stage 3: extend

| extend DNSCustomEntity = Query, IPCustomEntity = SrcIpAddr

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.

FieldKindValues
Queryin
  • dyn.com
  • dynu.com
  • dynv6.com
  • noip.com

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.

FieldSource
DNSCustomEntityextend
IPCustomEntityextend