Guide to the Secure Configuration and Administration of Microsoft ...

Chapter
7
Client Security and “Advanced Security”
Introduction
Chapter 2 described issues related to the installation of the Exchange client and Outlook
clients. This chapter will address other issues related to the clients, specifically
protection against malicious file attachments, the use of encryption to protect messages,
and methods that users can apply at the client to manage access to their mailboxes or
public folders.
File Attachment Security
Executable content is a term that refers to files or other objects that contain an
executable component. This executable component could serve a useful application or it
could be malicious – an example being a Word macro virus.
Both the Exchange client and the Outlook 97/98 client can be set to monitor mail
messages for some forms of executable content. Upon launching of these kinds of
executable content, the client will provide notification that an executable is about to
launched and offer the opportunity to cancel the action. Outlook 98 also offers, via patch
O98secu.exe, the ability to strip attachments from incoming mail messages as described
in Chapter 2.
Note that the option to monitor for executables only exists in recent versions of the clients
-- Outlook 97 version 8.02 or higher, Exchange client version 5.0.1458 or higher, and
Outlook 98. Attachment blocking is only available in Outlook 98 with the O98secu.exe
patch installed.
To enable file attachment security:
Exchange Client Outlook 97 Outlook 98
Verify the proper versions of Outlook 97 and/or the Exchange client are being used --
Outlook version 8.02 or higher and Exchange client version 5.0.1458 or higher.
Verify the option to check for executable file attachment is enabled (which is the
default). From the client, select Tools/Options and the “Attachments” tab. Under
“Security Method,” select the option “High.”
Please note that file attachment security, while useful, is limited.
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