About this article
This article is created using an automated generation workflow leveraging generative AI. It reviews the PowerShell FileSystem Provider and Get-Content Stream feature, limiting the steps to reading the Zone.Identifier without deleting it. It has not been re-executed on an actual Windows machine.Verification status: 📘 Official specification confirmed / Windows physical machine unverified
Information confirmation date: October 2, 2026. It is also normal for files not to have a Zone.Identifier.
If warnings only appear for files obtained from a browser or similar sources, one clue is the NTFS alternate data stream.
Listing streams
$path = '.\sample.txt' Get-Item -LiteralPath $path -Stream *
If a Zone.Identifier exists, check it in read-only mode.
Get-Content -LiteralPath $path -Stream Zone.Identifier
This sample does not delete it.
Information separate from the main data
In NTFS, named streams can be maintained separately from the regular file body. A Zone.Identifier may be attached depending on the acquisition path.
Changing one place
Compare a local file created by yourself with a harmless file obtained from a browser.
flowchart LR A["ファイル"] --> B["既定データ"] A --> C["名前付きStream"] C --> D["Zone.Identifierがある場合"]
If using in a professional environment
Rather than suddenly changing the state with commands like Unblock, first record the stream and acquisition path for troubleshooting.
What does the presence of a Zone.Identifier reveal?
The Zone.Identifier uses a mechanism that can hold additional information as an NTFS named stream, rather than being part of the file body itself. Therefore, even files with identical content may differ in whether the stream exists depending on where they were obtained from.
The important point here is not to conclude safety or danger solely based on the presence or absence of a Zone.Identifier. When a warning occurs, it isOne of the investigation materialsFollowing the order of checking the acquisition path and stream, and avoiding the removal of information using Unblock-File before completing the necessary validation, makes it easier to trace the rationale later.
