Detection rules › Sigma

DNS-over-HTTPS Enabled by Registry

Severity
medium
Author
Austin Songer
Source
upstream

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

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1112 Modify Registry
Defense EvasionT1112 Modify Registry, T1140 Deobfuscate/Decode Files or Information

Event coverage

ProviderEvent IDTitle
Sysmon13RegistryEvent (Value Set)

Stages and Predicates

Stage 1: 1 of selection_edge

Details: 'DWORD (0x00000001)'
TargetObject|endswith: '\SOFTWARE\Policies\Microsoft\Edge\BuiltInDnsClientEnabled'

Stage 2: 1 of selection_chrome

Details: secure
TargetObject|endswith: '\SOFTWARE\Google\Chrome\DnsOverHttpsMode'

Stage 3: 1 of selection_firefox

Details: 'DWORD (0x00000001)'
TargetObject|endswith: '\SOFTWARE\Policies\Mozilla\Firefox\DNSOverHTTPS\Enabled'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Detailseq
  • DWORD (0x00000001) corpus 37 (sigma 37)
  • secure
TargetObjectends_with
  • \SOFTWARE\Google\Chrome\DnsOverHttpsMode
  • \SOFTWARE\Policies\Microsoft\Edge\BuiltInDnsClientEnabled
  • \SOFTWARE\Policies\Mozilla\Firefox\DNSOverHTTPS\Enabled