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:

Severity: low

Risk score: 21

Runs every: 5 minutes

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

Version: 3 (version history)

Added (Elastic Stack release): 7.16.0

Last modified (Elastic Stack release): 8.2.0

Rule authors: Austin Songer

Rule license: Elastic License v2

## Config

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.

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")