Protecting Against Macro Viruses

Setting Security Levels in Office Applications

Microsoft Word, Microsoft Excel, and Microsoft PowerPoint can be set to a high, medium, or low security level.

High security   Macros must be signed by a trusted source. Otherwise, macros in documents are automatically disabled without notice when the documents are opened. Word is set to the high security level by default.

Medium security   Users are prompted to enable or disable macros in documents when the documents are opened. Excel and PowerPoint are set to the medium security level by default.

Low security   No macro checking is performed when documents are opened and all macros are enabled. This security level is not recommended because no protection is active when it is selected.

To set the security level in Word, Excel, or PowerPoint

1. On the Tools menu, point to Macro, and then click Security.
2. Click the Security Level tab, and then select a security level.

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Specifying trusted sources

When you open a document with signed macros in Word, Excel, or PowerPoint, and the certificate has not previously been trusted, you can choose to trust the source. If you choose to trust the source, all documents with macros signed by that source are trusted and are automatically enabled when documents are opened, regardless of the security level set for the application.

You can choose to trust all installed add-ins and templates so that any files that are installed with Microsoft Office or added to the Office templates folder are trusted even though the files are not signed.

To specify trusted sources in Word, Excel, or PowerPoint

1. On the Tools menu in Word, Excel, or PowerPoint, point to Macro, and then click Security.
2. To view or remove sources that have been trusted, click the Trusted Sources tab.
3. To trust add-ins and templates that are installed with Office, select Trust all installed add-ins and templates check box.

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Presetting trusted sources for all users in your organization

To preset trusted sources on users’ computers, you can use the Profile Wizard to save your security settings. On a computer that has Office 2000 installed, open documents with macros signed by the sources you want to trust. Choose to trust the sources as you open each document.

Use the Profile Wizard to create an OPS file based on your configuration. Then use the Office Custom Installation Wizard to include your OPS file on the administrative installation point. When users run Office Setup from the administrative installation point, the sources that you specified as trusted sources are also specified as trusted sources on users’ computers.

Tip   You can use a system policy to preset security levels in Word, Excel, or PowerPoint. In the System Policy Editor, set the User\Microsoft application 2000\Tools | Macro\Security\Security Level policy. You can also set a system policy to specify whether to trust all installed add-ins and templates. In the System Policy Editor, set the User\Microsoft application 2000 \Tools | Macro\Security\Trust all installed add-ins and templates policy. For more information about the System Policy Editor, see Using the System Policy Editor.

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See also

You can use Windows NT Certificate Services to create and manage certificates. Windows NT Certificate Services is available in the Microsoft Windows NT 4.0 Option Pack. For more information about Windows NT Certificate Services, see Windows NT 4.0 Option Pack online Help.

For a list of certificate authorities that you can use, see the Microsoft Security Advisor Web site at http://backoffice.microsoft.com/securitypartners/.

You can use a virus scanning program and security levels with Microsoft Outlook® 2000 in the same way you can with Excel, Word, and PowerPoint. For more information, see Using Security Features in Outlook.

You can use the Profile Wizard to preset security levels and trusted sources. For more information, see Profile Wizard.

You can use the System Policy Editor to preset security levels and specify whether to trust installed add-ins and templates. For more information, see Using the System Policy Editor.