Detection rules › Kusto
Google DNS - Multiple errors to same domain
'Detects multiple errors to same domain.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Command & Control | T1095 Non-Application Layer Protocol |
Rule body kusto
id: da04a5d6-e2be-4cba-8cdb-a3f2efa87e9e
name: Google DNS - Multiple errors to same domain
description: |
'Detects multiple errors to same domain.'
severity: Medium
requiredDataConnectors:
- connectorId: GCPDNSDataConnector
dataTypes:
- GCPCloudDNS
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- CommandAndControl
relevantTechniques:
- T1095
query: |
let threshold = 2;
let err = dynamic(['NXDOMAIN', 'SERVFAIL', 'REFUSED']);
GCPCloudDNS
| where EventResultDetails in~ (err)
| summarize ips = makeset(SrcIpAddr) by Query, bin(TimeGenerated, 10m)
| where array_length(ips) >= threshold
| extend DNSCustomEntity = Query, IPCustomEntity = ips
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 threshold = 2;
let err = dynamic(['NXDOMAIN', 'SERVFAIL', 'REFUSED']);
Stage 1: source
GCPCloudDNS
Stage 2: where
| where EventResultDetails in~ (err)
Stage 3: summarize
| summarize ips = makeset(SrcIpAddr) by Query, bin(TimeGenerated, 10m)
Stage 4: where
| where array_length(ips) >= threshold
Stage 5: extend
| extend DNSCustomEntity = Query, IPCustomEntity = ips
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 |
|---|---|---|
EventResultDetails | in |
|
ips | ge |
|
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 |
|---|---|
Query | summarize |
ips | summarize |
DNSCustomEntity | extend |
IPCustomEntity | extend |