Detection rules › Kusto

Google DNS - Multiple errors for source

Severity
medium
Time window
10m
Group by
SrcIpAddr
Source
github.com/Azure/Azure-Sentinel

'Detects multiple errors for the same source IP address.'

MITRE ATT&CK coverage

TacticTechniques
Command & Control

Rule body

id: 7e81a935-5e91-45a5-92fd-3b58c180513b
name: Google DNS - Multiple errors for source
description: |
  'Detects multiple errors for the same source IP address.'
severity: Medium
requiredDataConnectors:
  - connectorId: GCPDNSDataConnector
    dataTypes:
      - GCPCloudDNS
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CommandAndControl
relevantTechniques:
  - T1095
query: |
  let threshold = 10;
  let err = dynamic(['NXDOMAIN', 'SERVFAIL', 'REFUSED']);
  GCPCloudDNS
  | where EventResultDetails in~ (err)
  | summarize count() by SrcIpAddr, bin(TimeGenerated, 10m)
  | where count_ > threshold
  | extend IPCustomEntity = SrcIpAddr
entityMappings:
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: IPCustomEntity
version: 1.0.0
kind: Scheduled

Stages and Predicates

Parameters

let threshold = 10;
let err = dynamic(['NXDOMAIN', 'SERVFAIL', 'REFUSED']);

Stage 1: source

GCPCloudDNS

Stage 2: where

| where EventResultDetails in~ (err)

Stage 3: summarize

| summarize count() by SrcIpAddr, bin(TimeGenerated, 10m)

Stage 4: where

| where count_ > threshold

Stage 5: extend

| extend IPCustomEntity = SrcIpAddr

Indicators

These rows show field, operator, and value matches.

Output fields

These fields are emitted when the rule matches.

FieldSource
SrcIpAddrsummarize
IPCustomEntityextend