DNS-over-HTTPS Enabled via Registry

Elastic Stack Serverless Security

Identifies when a user enables DNS-over-HTTPS. This can be used to hide internet activity or the process of exfiltrating data. With this enabled, an organization will lose visibility into data such as query type, response, and originating IP, which are used to determine bad actors.

Rule type: eql

Rule indices:

• winlogbeat-*
• logs-endpoint.events.*
• logs-windows.*

Severity: low

Risk score: 21

Runs every: 5m

Searches indices from: now-9m (https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math[Date Math format], see also Additional look-back time)

Maximum alerts per execution: 100

References:

• https://www.tenforums.com/tutorials/151318-how-enable-disable-dns-over-https-doh-microsoft-edge.html
• https://chromeenterprise.google/policies/?policy=DnsOverHttpsMode

Tags:

• Elastic
• Host
• Windows
• Threat Detection
• Defense Evasion

Version: 5

Rule authors:

• Austin Songer

Rule license: Elastic License v2

registry where event.type in ("creation", "change") and
  (registry.path : "*\\SOFTWARE\\Policies\\Microsoft\\Edge\\BuiltInDnsClientEnabled" and
  registry.data.strings : "1") or
  (registry.path : "*\\SOFTWARE\\Google\\Chrome\\DnsOverHttpsMode" and
  registry.data.strings : "secure") or
  (registry.path : "*\\SOFTWARE\\Policies\\Mozilla\\Firefox\\DNSOverHTTPS" and
  registry.data.strings : "1")

Framework: MITRE ATT&CKTM

• Tactic:

  • Name: Defense Evasion
  • ID: TA0005
  • Reference URL: https://attack.mitre.org/tactics/TA0005/

• Technique:

  • Name: Impair Defenses
  • ID: T1562
  • Reference URL: https://attack.mitre.org/techniques/T1562/