There’s been a bit of back and forth since the change was originally announced, but this week Microsoft began rolling out an update to Microsoft Office that blocks the use of Visual Basic for Applications (VBA) macros in documents downloaded
Microsoft was testing the new default settings last month when it suddenly rolled back the update, “temporarily while we make some additional changes to improve usability.” Although it was said to be temporary, many experts were concerned that Microsoft would not change the default settings, leaving systems vulnerable to attack. Google’s threat analysis group leader, Shane Huntley, tweeted: “Blocking Office macros would do infinitely more to defend against real threats than all the threat intelligence blog posts.”
The new default setting is now being implemented, but with updated language to let users and administrators know what options they have when they try to open a file and it’s locked. This only applies if Windows, using the NTFS file system, notices it as downloaded from the Internet and not a network drive or site that administrators have marked as safe, and it doesn’t change anything on other platforms like Mac, Office on Android / iOS or Office on the web.
Microsoft:
We resume rolling out this change to the current channel. Based on our review of customer feedback, we’ve made updates to both our end-user and IT administration documentation to clarify what options you have for different scenarios. For example, what to do if you have files in SharePoint or files on a network share. See the following documentation:
• For end users, a potentially dangerous macro has been blocked
• For IT administrators, Internet macros will be blocked by default in Office
If you’ve ever enabled or disabled Block Macro Execution on Office files from Internet Policy, your organization won’t be affected by this change.
While some people use the scripts to automate tasks, hackers have abused the feature with malicious macros for years, tricking people into downloading a file and running it to compromise their systems. Microsoft noted how administrators could use Group Policy settings in Office 2016 to block macros on their organization’s systems. Still, not everyone activated it, and attacks continued, allowing hackers to steal data or distribute ransomware.
Users who try to open files and are blocked will get a pop-up that sends them to this page, explaining why they probably don’t need to open this document. It starts by going through several scenarios where someone might try to trick them into running malware. If they really need to see what’s inside the downloaded file, it goes on to explain ways to access it, all of which are more complicated than before, where users could normally enable macros by pressing a button on the warning banner.
This change may not always prevent someone from opening a malicious file, but it provides several more layers of warning before they can get to it, while giving access to people who say they absolutely need it.