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Network Posture

github-actions[bot] edited this page Aug 26, 2026 · 1 revision

Machine network posture

A system backend, and one of the Windows layers — the only one that is off by default. It reads incident-response material rather than supply-chain material, so it is asked for:

postmortem system --manager network --deep

Without --deep the layer refuses rather than quietly returning nothing.

What is read

Reading Finding Severity
A non-comment line in hosts A name redirected by hand Medium
A system-wide WinHTTP proxy Medium
A netsh port proxy A pivot on the machine itself High
A DNS-over-HTTPS resolver Windows does not ship High
A root certificate issued in the last three years Medium
An inbound firewall rule for a non-Windows program Recorded Info

Three readings that need calibrating

DNS-over-HTTPS

A stock machine has 12 DoH servers configured, and every one is a template Windows ships — Quad9, Google, Cloudflare. A resolver worth reporting is one that is not among them.

Firewall rules

156 inbound Allow rules are enabled, of which 138 carry a Group — they belong to a Windows feature. The 18 without one are the third-party applications: browsers, games, launchers. They are recorded at Info and scored at nothing; what admits them is ordinary desktop software.

Root certificates — what postmortem cannot tell you

A trusted root CA is what makes TLS interception invisible, so it belongs here. But postmortem cannot separate a root that shipped with Windows from one that was added, offline:

  • Issuer names do not work. Microsoft's own roots sign as O=MSFT, O=Microsoft Trust Network, and even CN=Symantec Enterprise Mobile Root for Microsoft. Any exclusion list built from what you happen to see misses the rest.
  • The AuthRoot thumbprint list does not work either. 12 of a stock machine's 39 roots are absent from it — and all 12 are Microsoft roots built into the OS. AuthRoot holds the auto-updated third-party program, not the shipped set.

What is measurable is age. The most recently issued legitimate root on the reference machine dates from 2021 — six years old. A root generated in the last three years has the shape of an interception CA, and that is the only claim made.

The store size is reported as a caveat so the limitation is stated rather than implied:

39 certificates are trusted as root CAs. postmortem cannot tell offline which of
them shipped with Windows and which were added, so only those issued in the last
three years are reported

Not covered yet

Listening sockets bound to an unsigned binary (Get-NetTCPConnection joined to its owning process), IP Helper and 6to4 configuration.

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