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by John W. Simek, Vice President of Sensei Enterprises, Inc.

7-Zip Supports Windows ‘Mark-of-the-Web’ File Flag

June 22, 2022

7-Zip is a free open source file compression utility. You can even use the software in a commercial setting. BleepingComputer reported that 7-Zip has finally added support for the Windows ‘Mark-of-the-Web’ (MoTW) security feature. When you download a file from the internet or another computer, it is tagged as coming from a foreign source and could be a risk to open it. Microsoft Office will open the file in Protected View, which means the file is read-only and any macros are disabled. 7-Zip now supports propagating the MoTW file flag to files extracted from a downloaded archive.

Unfortunately, the feature is disabled by default. In other words, you are at risk if you open an extracted file from a downloaded compressed file. In order to enable the feature, go to Tools, Options and change the value for Propagate Zone.Id stream. Changing the setting to Yes will preserve the MoTW for all files. A less secure option is to select For Office files. I really don’t understand why the default setting isn’t set to Yes.

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