Block macros from running in Office files from the internet
This per-user policy value controls whether Microsoft Word blocks VBA macros in files identified as originating from the internet.
since 0.9.8.11
Purpose
Show registry keys (1)
HKCU\software\policies\microsoft\office\16.0\word\security\blockcontentexecutionfrominternet
This per-user policy value controls whether Microsoft Word blocks VBA macros in files identified as originating from the internet. Such files commonly include browser downloads and email attachments carrying Mark of the Web (MOTW). Files opened from a network share can also be affected when Windows classifies the location in the Internet zone rather than as Local intranet or a Trusted site.
The value is a REG_DWORD. A value of 1 enables the policy: Word prevents the macros from running even when Enable all macros is selected in the Trust Center macro settings. The user is notified that macros were blocked because the file came from an untrusted source. The policy blocks macro execution; it does not itself prevent the document from being opened.
A value of 0 disables this specific blocking policy. Other Trust Center settings and macro policies then determine whether the macros can run. Setting the value to 0 does not, by itself, enable all macros.
Notes
Security
Enabling the policy reduces the risk of malicious VBA code running from downloaded documents, email attachments, or untrusted network sources. Such code can act with the signed-in user's permissions and might download malware, modify files, or access data available to that user.
This setting is not a universal macro prohibition. Files in a Trusted Location and macros that are validly signed by a publisher trusted on the device can be exempt from the internet-origin block. Other Office applications use separate policy values.
Possible side effects
Legitimate macros in Word documents and templates obtained from the internet cannot run. As a result, automated workflows, forms, and other macro-dependent document features might stop working. Internal files can also be affected when their network location is not recognized as Local intranet or trusted.
Notes
Source classification relies primarily on Mark of the Web and Windows security zones. For locally stored files, MOTW requires a file system capable of preserving the associated alternate data stream, notably NTFS.
An absent value is not necessarily equivalent to 0. Current supported versions of Microsoft 365 Apps also block macros from the internet by default when the policy is not configured. Default behavior can differ in older perpetual Office releases and at different update levels.
Microsoft documentation
Microsoft Learn: Macros from the internet are blocked by default in Office