↳ GitHub sourceAnalytics ruleHigh
Tailscale: Split-DNS configuration modified
Description
Identifies when the tailnet split-DNS configuration is modified. Split-DNS overrides per-domain resolution within the tailnet - an attacker adding a new domain mapping or changing the resolver IP can hijack DNS for that domain.
- Rule type
- Scheduled
- Version
- 1.0.0
- Declared status
- Available
- Query frequency
- 15m
- Query period
- 15m
- Trigger
- gt 0
Declared MITRE coverage
Declared sources
Metadata from the source file. No dependencies inferred from KQL.
Connectors
Data types
KQL query
Original query, unchanged.
Tailscale_Audit_CL
| where Action == "UPDATE"
| where tostring(Target.type) == "TAILNET"
| where tostring(Target.property) == "DNS_SPLIT_DNS"
| extend ActorLogin = tostring(Actor.loginName)
| extend OldDomains = bag_keys(Old)
| extend NewDomains = bag_keys(New)
| extend AddedDomains = set_difference(NewDomains, OldDomains)
| extend RemovedDomains = set_difference(OldDomains, NewDomains)
| project TimeGenerated, ActorLogin, AddedDomains, RemovedDomains, Old, New, Origin
Declared entities
Related content
Links established from declared identifiers and solution manifests.
Source provenance
GitHubDisplayed values come from files in Azure/Azure-Sentinel. They describe the published template, not your workspace configuration.
- Commit
9800e51↗- Source identifier
b4c5d6e7-1234-5678-90ab-cdef12345010
GSTEP / CATALOG TRACKING
Added to catalog : 16 Sept 2026 · 05:49 UTC
Last change observed : 16 Sept 2026 · 05:49 UTC