Microsoft Security Tool Kit: Securing an Existing Windows NT 4.0 System

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For the purposes of this guide, we are assuming that the existing installation has not been compromised. If a system has been compromised, you need to follow the recommendations for fixing that system before you can begin the following baseline steps. For more information about how to find out if your system or network has been compromised, click here.

The information in this guide applies to:

  • Microsoft Windows NT Server 4.0, Enterprise Edition

  • Microsoft Windows NT Workstation 4.0

  • Microsoft Windows NT Server 4.0

On This Page

Step 1: Determining the Current State
Step 2: Securing the System
Step 3: Securing the System continued
Step 5: Ongoing Maintenance Program

Step 1: Determining the Current State

It is often difficult to determine the current state of an existing installation. Besides knowing which individual patches have been applied, you need to know which services are running.

  • Because Web servers are particularly susceptible to security attacks, Internet Information Server (IIS) should be disabled if the system is not being used as a Web server.

  • It is important to identify which applications and service packs are running on the system. Microsoft specifically recommends that you identify which service pack you are running on the operating system, Internet Explorer, and IIS.

  • The Hfnetchk tool should be used to determine which security fixes are currently installed.

Step 2: Securing the System

With your operating system up and running, it is time to make it more secure. Depending on the state of your system (determined in Step 1), you might be able to skip some of the following steps.

Step 3: Securing the System continued

To continue securing your system, you must follow the checklists below that apply to your installation.

Microsoft Internet Information Server 4 Security Checklist

Microsoft Windows NT Server 4.0 Security Checklist

Microsoft Windows NT Workstation 4.0 Security Checklist

Step 4: Securing Internet Information Server

You now have a good baseline of security patches installed. Web servers are particularly susceptible to security attacks, and Microsoft has provided the IIS Lockdown tool to help you. Please follow this step if IIS will be running on this system.

  • Run the IIS Lockdown Wizard.

    This tool lets you instantly configure an IIS 4.0 or 5.0 Web server for secure operation. It includes server role templates for Microsoft Exchange, Commerce Server, BizTalk, Small Business Server, SharePoint Portal Server, FrontPage Server Extensions, and SharePoint Team Server. The tool provides an Undo feature that allows the effects of the most recent lockdown to be reversed. It also screens all incoming requests to an IIS Web server and allows only those that comply with a ruleset created by the administrator to pass. This significantly improves the security of the server by helping ensure that it responds only to valid requests. The tool allows the administrator to filter requests based on length, character set, content, and other factors. A default ruleset is provided, which can be customized to meet the needs of a particular server.

Note: All SRP and post-SRP security hotfixes should be applied before and after the use of the IIS Lockdown Tool.

Step 5: Ongoing Maintenance Program

Your system has now been installed with a good security baseline, but without ongoing maintenance, your system can become vulnerable to new forms of attacks.

  • Use the Hfnetchk tool to assess which security fixes have been applied to the Windows NT 4.0 operating system, as well as security fixes for Internet Information Server 4.0, SQL Server 7.0, SQL Server 2000 (including Microsoft Data Engine—MSDE), and Internet Explorer 5.01 or later.

    When you run the Hfnetchk tool after installing the security baseline described above, the Hfnetchk results will show many security fixes are not installed. This is true and expected. The document provides only a baseline from which to start. It is recommended that you take the necessary steps to ensure all the critical security patches are installed.

    You should run this tool against all the computers that you are securing on a daily basis until you are confident that all the recommended fixes have been applied. Then, you can lower the frequency. As you deploy new security fixes, you should continue to run the tool to verify and detect missing security patches.

    Note: Although it does not run natively on NT 4.0, consider running Microsoft's Baseline Security Analyzer (MBSA) from a Windows 2000 or XP machine to analyze multiple networked NT 4.0 machines at once. Besides revealing missing patches and updates, the MSBA will look for common vulnerabilities and recommend solutions.

  • Subscribe to the Microsoft Security Notification Service. This is a free email notification service that Microsoft uses to send information to subscribers about the security of Microsoft products.

  • Use the Microsoft Update Web site to check for the latest Recommended and Critical updates.

  • As new security fixes become available, it is important to apply these new fixes. Microsoft has created the Qchain tool to chain hotfixes together in order for only one reboot to be required when installing several fixes.