Digital Guardian - Exfiltration using DNS protocol

Status: available
Severity: high
Time window: 1h
Source: github.com/Azure/Azure-Sentinel

'Detects exfiltration using DNS protocol.'

MITRE ATT&CK coverage

Tactic	Techniques
Exfiltration	`T1048` Exfiltration Over Alternative Protocol

Rule body

id: 39e25deb-49bb-4cdb-89c1-c466d596e2bd
name: Digital Guardian - Exfiltration using DNS protocol
description: |
  'Detects exfiltration using DNS protocol.'
severity: High
status: Available
requiredDataConnectors:
  - connectorId: SyslogAma
    datatypes:
      - Syslog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Exfiltration
relevantTechniques:
  - T1048
query: |
  DigitalGuardianDLPEvent
  | where DstPortNumber == 53
  | extend AccountCustomEntity = SrcUserName
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: AccountCustomEntity
version: 1.0.2
kind: Scheduled

Stages and Predicates

Stage 1: `source`

DigitalGuardianDLPEvent

Stage 2: `where`

| where DstPortNumber == 53

Stage 3: `extend`

| extend AccountCustomEntity = SrcUserName

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`DstPortNumber`	eq	`53`	`field:"DstPortNumber" kind:eq value:"53"`

Output fields

These fields are emitted when the rule matches.

Field	Source
`AccountCustomEntity`	`extend`

Digital Guardian - Exfiltration using DNS protocol

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`