Block macros from running in Office files from the internet
This per-user registry value controls whether Microsoft Publisher blocks macros in files obtained from untrusted internet sources.
since 0.9.8.11
Purpose
Show registry keys (1)
HKCU\software\policies\microsoft\office\16.0\publisher\security\blockcontentexecutionfrominternet
This per-user registry value controls whether Microsoft Publisher blocks macros in files obtained from untrusted internet sources. The Office Administrative Templates define it as a REG_DWORD: 1 enables the block, while 0 disables this policy-enforced block.
Office normally identifies an internet-sourced file through Mark of the Web zone information recorded by Windows. This commonly applies to files downloaded by a browser or saved from an email attachment. When blocking is enabled, Publisher prevents macros in the affected file from running and notifies the user.
Notes
Additional effects
The policy-enforced block takes precedence over a Trust Center selection that would otherwise allow all macros. The user therefore cannot override it merely through Publisher’s normal content warning.
Office evaluates some established trust decisions separately. Macros can still run when the file is in a Trusted Location, was previously made a Trusted Document, or contains a valid signature whose certificate is installed as a Trusted Publisher.
Security
Blocking internet-sourced macros reduces exposure to malicious VBA code delivered in Publisher files. A successful malicious macro can operate with the signed-in user’s permissions and may access that user’s data and other resources available to the account.
This value does not scan macros for malicious behavior, nor does it prevent the file itself from being opened or edited. Files exempted through Trusted Locations, prior document trust, or Trusted Publishers can still execute their macros. The security of those trust mechanisms—particularly write access to Trusted Locations and control of Trusted Publisher certificates—therefore affects the protection provided.
Possible side effects
Legitimate Publisher files obtained from the internet can lose VBA-based automation. Features, calculations, or business processes that depend on those macros might not operate, even though the remaining file content can still be opened and edited.
Notes
The value applies to the current user and specifically to Publisher in the Office 16.0 product branch. It does not impose the same setting on Word, Excel, or other Office applications, which use separate application-specific registry paths.
An absent value is not necessarily equivalent to a value of 0 in every Office release. Recent Microsoft 365 Apps versions can block macros from the internet by default. When the policy value is absent, effective behavior can therefore depend on the installed Office version and its default or Trust Center settings.
Microsoft documentation
Microsoft Learn: Macros from the internet are blocked by default in Office
Microsoft Download Center: Administrative Template files for Microsoft Office