WinGet

WinGet

A system backend, and one of the five Windows layers. Reads WinGet's configured sources, its installed table, and the admin settings that govern how much it verifies.

Data sources

Command	Used for
winget source export	Configured sources as JSON lines (name, URL, type, trust level).
winget list --disable-interactivity	The installed table across every layer WinGet sees.
winget --info	The admin settings that weaken verification.

winget export is deliberately not used. It silently drops every package it cannot resolve to a source - which is exactly the set worth looking at:

Installed package is not available from any source: NVIDIA Control Panel

Reading the installed table

winget list has no machine-readable output, so the table is parsed from its own header on every run (WinGet sizes columns to their content, so the offsets are not constant). Two rules matter:

• Slicing is by character, not byte. A localized Name column is multi-byte in UTF-8, and byte offsets cut the following Id in half.
• The Name column is never an identity. It is localized - a French machine reports Bloc-notes Windows. Id is stable.

The Id prefix says which layer an entry came from:

Id shape	Layer
Microsoft.AppInstaller	A package WinGet resolves to one of its sources.
MSIX\...	An MSIX/AppX package.
ARP\Machine\...	A registry Uninstall entry, machine scope.
ARP\User\...	A registry Uninstall entry, per-user scope.

Risk signals

Signal	Severity	Meaning
unmanaged-by-winget	Info	WinGet does not govern this entry (MSIX or registry).
user-scope install (writable without elevation)	Low	Installed under ARP\User.
outdated (installed → current)	Low	WinGet's Available column reports a newer release.

unmanaged-by-winget is Info at 0 points on purpose. On a stock machine 53 of 88 entries are MSIX or registry entries that WinGet was never going to manage; scoring that would light up two thirds of every scan and mean nothing. A genuine shadow install - a package WinGet knows that was installed around it - needs cross-referencing, which Add/Remove Programs does.

Source trust

--repos lists the configured sources. A source is judged on its trust level and URL host, never on its name:

{"Name":"winget","Type":"Microsoft.PreIndexed.Package","TrustLevel":["Trusted","StoreOrigin"]}

A stock Windows ships three Microsoft sources, not two: winget, msstore and winget-font. An allowlist of the first two reports a third-party source on a clean install.

A source outside Microsoft's is surfaced as a caveat, with its type explained - a custom Microsoft.PreIndexed.Package outranks a custom REST source, because its MSIX index is signed by a certificate somebody made this machine trust.

Admin settings

winget --info reports the settings that trade away a guarantee. Each is reported as a caveat when enabled:

Setting	Severity	What it costs
InstallerHashOverride	Critical	The SHA256 in a manifest stops being binding.
LocalManifestFiles	High	Packages installable from arbitrary local manifests.
BypassCertificatePinningForMicrosoftStore	High	Store traffic is open to interception.
LocalArchiveMalwareScanOverride	High	The malware scan on local archives can be skipped.
ConfigurationProcessorPath	High	A custom configuration processor loads from an arbitrary path.
ProxyCommandLineOptions	Medium	A per-invocation proxy can redirect where installers are fetched from.

The Group Policy key (HKLM\SOFTWARE\Policies\Microsoft\Windows\AppInstaller) is absent on an unmanaged machine; both cases are handled.

Not covered yet

Manifest SHA256 verification, InstallerType, and InstallerUrl domain checks need the manifest itself - that is inspect --deep territory. Per-package community-vs-Store provenance and winget pin are not read.