6 Advanced Tips for Securing Applications with EMET
Understanding the Enhanced Mitigation Experience Toolkit (EMET)
Microsoft’s Enhanced Mitigation Experience Toolkit (EMET) represents a powerful, yet often overlooked, security resource. Installation of EMET is straightforward, enabling rapid protection for a wide range of commonly used applications.
However, the true potential of EMET extends far beyond its initial setup. Users can significantly enhance their security posture through more advanced configuration and troubleshooting.
EMET's Hands-Off Approach
A key characteristic of EMET is its non-intrusive operation. Unlike some security solutions, EMET operates silently in the background, without prompting the user with frequent alerts or requests.
This "set-it-and-forget-it" functionality is beneficial, but it also necessitates a proactive approach to ensuring optimal performance and compatibility.
Expanding Application Coverage with EMET
While EMET provides default protections, expanding the scope of protected applications is crucial. This involves manually adding applications that aren't automatically covered.
Careful consideration should be given to the specific mitigations applied to each application, balancing security with functionality.
Troubleshooting Application Compatibility Issues
Occasionally, EMET’s mitigations can cause compatibility problems with certain applications. When this occurs, systematic troubleshooting is required.
Identifying the specific mitigation causing the issue and adjusting it, or creating an exception, can restore application functionality without compromising security.
Advanced EMET Configuration
- Mitigation Control Flow Guard (CFG): This feature helps prevent exploits that hijack the control flow of a program.
- Data Execution Prevention (DEP): DEP marks memory regions as non-executable, hindering the execution of malicious code.
- Address Space Layout Randomization (ASLR): ASLR randomizes the memory addresses used by a program, making it harder for attackers to predict locations of critical data.
Understanding and appropriately configuring these mitigations is essential for maximizing EMET’s effectiveness.
Regularly reviewing and updating EMET configurations is recommended to address emerging threats and maintain a robust security posture.
Determining Application Conflicts with EMET
Related: Rapidly Enhance Computer Security Utilizing Microsoft’s Enhanced Mitigation Experience Toolkit (EMET)
When an application attempts an action prohibited by your configured EMET rules, the toolkit will terminate the application – this is the standard operational mode. EMET proactively closes applications exhibiting potentially hazardous behavior, preventing the execution of exploits. The Windows operating system does not universally implement this behavior to avoid compatibility issues with legacy software.
Should an application encounter a conflict, it will be immediately closed, and a notification will appear from the EMET icon located in the system tray. Details regarding these events are also recorded within the Windows event log; the reporting parameters can be adjusted via the Reporting section on the EMET window’s ribbon.
Leveraging the Benefits of a 64-bit Windows Operating System
Related: Enhanced Security Advantages of Utilizing the 64-bit Windows Version
Employing a 64-bit edition of Windows provides heightened security capabilities, primarily due to its support for advanced features such as address space layout randomization (ASLR). These crucial security enhancements are not fully accessible when operating with a 32-bit Windows installation.
Similar to the operating system itself, the security functionalities of EMET (Enhanced Mitigation Experience Toolkit) are significantly more robust and effective on computers running a 64-bit architecture.
The expanded address space offered by 64-bit systems allows for more effective implementation of security measures. This ultimately contributes to a more resilient computing environment.
Understanding Address Space Layout Randomization (ASLR)
ASLR is a vital security technique. It helps prevent exploitation attempts by randomly positioning key data areas of a process in memory.
This randomization makes it considerably more difficult for attackers to reliably execute malicious code. A 64-bit system's larger address space allows for a greater degree of randomization, strengthening this defense.
EMET and 64-bit Compatibility
EMET is designed to provide additional layers of security. Its features are optimized for the 64-bit environment.
The toolkit’s mitigations function more comprehensively on 64-bit PCs. This results in a more substantial reduction in the attack surface and improved overall system protection.
Securing Individual Processes
Rather than applying security measures to the entire system, it is often more effective to focus on specific applications. Prioritize those applications that are most vulnerable to compromise. This includes commonly targeted software like web browsers, browser extensions, instant messaging clients, and any program that interacts with the internet or processes downloaded files.
Applications operating offline, or those that do not open downloaded files, generally present a lower risk profile. If a critical business application with internet access exists, it should be considered a high-priority target for security enhancements.
To implement security for a currently running application, find it within the EMET interface, right-click on its entry, and choose "Configure Process."
(Should you need to secure a process that isn't actively running, navigate to the Apps window and utilize the "Add Application" or "Add Wildcard" options.)
The Application Configuration window will then open, with the selected application already highlighted. All security rules are enabled by default. Simply click "OK" to implement these rules.
In the event that an application malfunctions after applying these settings, revisit this window and attempt to disable restrictions individually. Disable them one at a time until the application functions correctly, allowing you to pinpoint the source of the conflict.
If you wish to completely remove security restrictions from an application, select it from the list and click the "Remove Selected" button. This will revert the application to its original, default security state.
Adjusting Global Security Policies
Within the System Status area, you have the capability to define rules that apply across the entire system. Generally, maintaining the default configurations is recommended, as these allow individual applications to choose whether or not to utilize these security features.
For heightened security, options like "Always On" or "Application Opt Out" can be selected for these settings. However, be aware that this approach may lead to compatibility issues with numerous applications, particularly older software. Should applications begin to function incorrectly, you can always return to the default settings or establish specific exceptions.
Creating Application Exceptions
To establish an exception for a specific application, locate the process, right-click on it, and choose "Configure Process." Then, deselect the particular protection mechanism you wish to disable – for example, to exclude an application from system-wide ASLR, uncheck the "MandatoryASLR" and "BottomUpASLR" boxes.
Confirm your changes by clicking "OK" to save the newly created rule.
It's important to remember that if "Always On" has been enabled for DEP, disabling it for individual processes within the Application Configuration window will not be possible.
Utilizing EMET Rules in Audit Mode
For those wishing to evaluate EMET rules without encountering potential disruptions, activating "Audit only" mode is recommended. Access the Application Configuration window through the Apps icon within the EMET interface.
A Default Action section is located on the ribbon at the screen's upper portion. Initially configured to "Stop on exploit"—meaning EMET will terminate an application upon rule violation—it can alternatively be set to "Audit only."
When an application triggers an EMET rule in this mode, the occurrence is logged, but the application's operation continues uninterrupted.
While this approach understandably negates the protective benefits of EMET’s active security measures, it provides a valuable method for rule validation prior to re-enabling "Stop on exploit" functionality.
Benefits of Audit Mode
- Allows for testing of rule configurations.
- Identifies potential compatibility issues.
- Minimizes disruption to workflow during testing.
By employing "Audit only" mode, administrators can refine their EMET rule sets, ensuring optimal security without risking application instability.
Rule Export and Import Capabilities
After the configuration and validation of your security rules, utilize the Export or Export Selected function to save them to a file. This file can subsequently be imported onto other computers you operate, replicating the same security measures without requiring repeated setup.
Within corporate environments, EMET rules, along with the EMET application itself, can be distributed via Group Policy configurations.
Implementing these advanced configurations is entirely optional. For home users preferring simplicity, a straightforward installation of EMET with the default recommended settings is perfectly sufficient.
- Rule Export: Allows saving configured rules to a file.
- Rule Import: Enables applying saved rules to other systems.
- Group Policy Deployment: Facilitates centralized management in corporate settings.
The ability to export and import rules streamlines the process of maintaining consistent security across multiple machines. This is particularly beneficial for users who work on several PCs.
Furthermore, the integration with Group Policy offers a scalable solution for organizations seeking to enforce security standards across their entire network. This ensures a uniform level of protection for all endpoints.
Simplified Security for Home Users
It’s important to remember that these advanced features aren’t essential for everyone. If you are a home user and prefer a less complex approach, simply installing EMET and accepting the default settings will provide a significant layer of security.
The default settings are designed to offer broad protection against common exploits and vulnerabilities, making EMET effective even without extensive customization. This ease of use is a key benefit for less technically inclined users.