Configuring Antivirus Protection

Microsoft Windows SharePoint Services now allows you to help protect your users from uploading or downloading files that contain viruses. When you have installed an antivirus scanner that is compatible with Windows SharePoint Services, you can enable the antivirus protection feature for your server. When you enable the antivirus protection feature, files are checked for viruses when a user adds a document to a document library or list, or when a user views a document in a document library or list. If a virus is found, the scanner attempts to clean the file, or if the file cannot be cleaned, blocks the file from being added or viewed.

 Note   If a file is uploaded, and is later identified as containing a virus, users will not be able to open the file. In this situation, however, users may still be able to save the file locally and open it from their computer.

You enable and configure antivirus protection at the server level. When enabled, antivirus protection is available for all document libraries on all sites and subsites on your server, or for all servers in your server farm. You can use HTML Administration pages or the command line tool to configure antivirus protection.

You must install Windows SharePoint Services-compatible antivirus software on any server computer running Windows SharePoint Services before you can enable antivirus protection in Windows SharePoint Services. If you are in a server farm configuration, antivirus software must be installed on every Web front-end server in the server farm. Consult your antivirus software vendor to find out whether they offer a virus scanner for use with Windows SharePoint Services and for information about installing the virus scanner. Or, for a list of antivirus software vendors that support antivirus protection for Windows SharePoint Services, see the Windows SharePoint Services Partners Site.

Using HTML Administration Pages to Configure Antivirus Settings

You use the Configure Antivirus Settings page in the SharePoint Central Administration pages to enable and configure antivirus protection.

Enable antivirus protection for your server or server farm
  1. Click Start, point to All Programs, point to Administrative Tools, and then click SharePoint Central Administration.
  2. On the SharePoint Central Administration page, under Security Configuration, click Configure antivirus settings.
  3. Select the Scan documents on upload check box.
  4. Select the Scan documents on download check box.
  5. If desired, select the Attempt to clean infected documents check box.
  6. If you want to allow users to save infected files locally, select the Allow users to download infected documents check box.

 Note   This option is disabled by default to prevent users from saving potentially infected files to their client computers.

  1. In the Time out scanning after ___ seconds box, type the number of seconds to allow before timing out the scanning process.

The default time is 300 seconds, or 5 minutes. This should be enough time to allow the antivirus processes to finish without affecting performance. The default time is recommended, but you can adjust this time if you are experiencing performance issues.

  1. In the Allow scanner to use up to ___ threads box, type the number of threads to allow the scanning process to take up.

By default, the number of threads is set to 5, which should be sufficient for even a large number of sites. The default number of threads is recommended, but you can adjust the number of threads if you are experiencing performance issues.

  1. Click OK.

Using the Command Line to Configure Antivirus Settings

You can also configure antivirus protection by setting properties on the command line. To set a property, you use the Stsadm.exe tool with the setproperty operation. The following properties are available for use in configuring antivirus protection.

Property name Description Values
avallowdownload Specifies whether users can download infected documents to their client computers. yes/no
avcleaningenabled Specifies whether antivirus cleaning is enabled or disabled. yes/no
avdownloadscanenabled Specifies whether documents are scanned on download. yes/no
avnumberofthreads Specifies the number of threads to use for antivirus processes. A numerical value, the number of threads to use.
avtimeout Specifies how long to wait before timing out an antivirus process. A numerical value, in seconds.
avuploadscanenabled Specifies whether documents are scanned on upload. yes/no

The following example shows the syntax to use when setting an antivirus property:

stsadm.exe -o setproperty -pn <property name> -pv <property value>

For example, to set the avtimeout property to 200, you would use the following syntax:

stsadm.exe -o setproperty -pn avtimeout -pv 200

For more information about setting properties using the command line, see "Introducing the Administration Tools for Windows SharePoint Services" in the Windows SharePoint Services Administrator's Guide.

 
 
Applies to:
Deployment Center 2003