Google DNS - Possible data exfiltration

Severity: high
Time window: 15m
Source: github.com/Azure/Azure-Sentinel

'Detects possible data exfiltration.'

MITRE ATT&CK coverage

Tactic	Techniques
Exfiltration	`T1567` Exfiltration Over Web Service

Rule body

id: 705bed63-668f-4508-9d2d-26faf4010700
name: Google DNS - Possible data exfiltration
description: |
  'Detects possible data exfiltration.'
severity: High
requiredDataConnectors:
  - connectorId: GCPDNSDataConnector
    dataTypes:
      - GCPCloudDNS
queryFrequency: 15m
queryPeriod: 15m
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Exfiltration
relevantTechniques:
  - T1567
query: |
  GCPCloudDNS
  | where Query has 'webhook.site'
  | 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

Stage 1: `source`

GCPCloudDNS

Stage 2: `where`

| where Query has 'webhook.site'

Stage 3: `extend`

| extend DNSCustomEntity = Query, IPCustomEntity = SrcIpAddr

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Query`	match	`webhook.site` transforms: `term`	`field:"Query" kind:match value:"webhook.site"`

Output fields

These fields are emitted when the rule matches.

Field	Source
`DNSCustomEntity`	`extend`
`IPCustomEntity`	`extend`

Google DNS - Possible data exfiltration

MITRE ATT&CK coverage

Rule body

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: extend

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend`