cloud34221.lol

Maximizing Performance on Windows Server 2016: Best Practices

Written by

admin

in

Windows Server 2016 Security Enhancements ExplainedWindows Server 2016 introduced a significant set of security improvements designed to reduce the attack surface, protect credentials and processes, and enable stronger isolation and control across on-premises and hybrid cloud environments. This article explains the major enhancements, how they work, deployment considerations, and best practices to help secure your Windows Server 2016 estate.

Overview: security goals in Windows Server 2016

Windows Server 2016 focuses on three broad security goals:

  • Reduce the attack surface by minimizing components and applying virtualization-based isolation.
  • Protect identities and credentials to prevent lateral movement and credential theft.
  • Protect the operating system and workloads with integrity checks, secure boot, and container isolation.

Credential protection: Credential Guard and Remote Credential Guard

Credential theft (LSASS dumping, Pass-the-Hash) is a common avenue for attackers. Windows Server 2016 adds two features to mitigate these threats.

  • Credential Guard

    • Uses virtualization-based security (VBS) and Hyper-V to isolate secrets such as Kerberos tickets and NTLM hashes in a secure, “virtualized” container outside the reach of the OS and common malware.
    • When enabled, LSASS secrets are stored in the isolated region; even if attackers obtain SYSTEM privileges in the host OS, they cannot extract those secrets easily.
    • Requires UEFI-based systems, Secure Boot, virtualization support, and Hyper-V role or Hyper-V isolation (can run on VMWare in some configurations but Microsoft support varies).

  • Remote Credential Guard

    • Protects credentials during RDP sessions by preventing credentials from being stored on or sent to the remote host.
    • When a user authenticates to a remote server, Remote Credential Guard ensures the user’s credentials remain on the client and Kerberos tickets are used for resource access where possible.
    • Useful for administrative sessions to remote servers and jump boxes.

Deployment notes:

  • Credential Guard can sometimes interfere with third-party software that needs to read credentials (e.g., some monitoring or backup agents). Test in lab before broad rollout.
  • Use Group Policy or Device Guard configuration to enable/disable Credential Guard policies.

Virtualization-Based Security (VBS) and Device Guard

Virtualization-Based Security leverages the hypervisor to create isolated regions of memory and execute code with higher trust. Two key features tie into VBS: Device Guard and Hypervisor-protected Code Integrity (HVCI).

  • VBS

    • Uses Hyper-V to create a secure execution environment, protecting secrets and sensitive code from the host OS.
    • Enables features like Credential Guard and HVCI.

  • Device Guard

    • Focuses on code integrity by allowing only trusted, signed, and authorized code to run.
    • Consists of two parts: hardware and firmware requirements (UEFI, Secure Boot) and code integrity policy that specifies allowed executables.
    • Helps block malware and unauthorized applications from executing, particularly in critical servers and kiosk scenarios.

  • Hypervisor-protected Code Integrity (HVCI)

    • Enforces code integrity checks within the VBS secure environment.
    • Prevents unsigned or improperly modified kernel-mode code from loading.
    • Can be used with virtualization-based security to protect the kernel from rootkits and other kernel-level attacks.

Deployment notes:

  • HVCI increases security but may require driver updates or whitelisting for incompatible kernel drivers.
  • Device Guard policies can be complex to craft; start with audit mode to discover what runs before enforcing.

Just Enough Administration (JEA) and Just-In-Time (JIT) administration

Limiting administrative privileges reduces risk. Windows Server 2016 includes features and guidance to practice least privilege.

  • Just Enough Administration (JEA)

    • Role-based access control for PowerShell that lets you create constrained endpoints exposing only the cmdlets and parameters necessary for specific tasks.
    • Administrators can delegate specific administrative tasks without giving full local admin rights.
    • Useful for reducing the blast radius of compromised accounts or accidental misconfiguration.

  • Just-In-Time (JIT) concepts

    • While JIT as a named feature is more commonly associated with Azure AD Privileged Identity Management, the operational practice applies on-premises: grant elevated rights only when needed and for limited time windows.
    • Combine JEA, scheduled tasks, and tight auditing to approximate JIT on Windows Server 2016.

Implementation tips:

  • Use JEA to create specific management endpoints for helpdesk and automation tasks.
  • Combine with Group Policy, event logging, and monitoring to detect misuse.

Shielded Virtual Machines and Host Guardian Service

Protecting VM data and state from a compromised or malicious fabric operator is critical in multi-tenant or outsourced datacenters.

  • Shielded VMs

    • Encrypt VM disks and state to prevent Hyper-V hosts or administrators from accessing VM contents.
    • Use BitLocker to protect VHD/VHDX files and virtual TPM (vTPM) to store keys.
    • Shielded VMs can run only on approved, healthy hosts.

  • Host Guardian Service (HGS)

    • A central service that attests to host health and grants keys to run shielded VMs only on trusted hosts.
    • Provides attestation modes: TPM-trusted attestation and AD-based attestation.
    • HGS typically runs on guarded cluster or independent service with strong physical and network protections.

Use cases and notes:

  • Ideal for service providers, multi-tenant datacenters, or scenarios where VM owners must trust their VMs remain confidential even from host admins.
  • Requires planning: HGS deployment, host attestation setup, and key management workflows.

Windows Defender improvements and attack surface reduction

Windows Server 2016 improves built-in antimalware and introduces features to reduce the exploitable surface.

  • Windows Defender

    • Server edition includes Windows Defender antimalware with real-time protection and integration with Windows Update for signature and platform updates.
    • Can be managed centrally via System Center, SCCM, or Group Policy.

  • Attack Surface Reduction (ASR) and Windows Firewall

    • Harden services by disabling unnecessary roles/features and using Windows Firewall with advanced rules to limit inbound connections.
    • Use AppLocker or Device Guard to restrict applications and scripts.
    • While ASR rules evolved further in later Windows/Defender ATP products, Server 2016 supports many hardening measures through GPO, SRP/AppLocker, and firewall rules.

Recommendations:

  • Turn on Windows Defender where possible; if using third-party AV, ensure proper management and exclusions for server workloads.
  • Harden server roles and minimize installed features and open ports.

Secure Boot, UEFI, and kernel protections

Windows Server 2016 requires newer platform capabilities to enable some security features.

  • Secure Boot and UEFI

    • Secure Boot ensures that only signed boot loaders and OS components execute during boot, preventing many bootkit/rootkit attacks.
    • Required for features like Credential Guard and Device Guard.

  • Kernel protections

    • Patch guard, driver signing enforcement, and HVCI together make kernel-level compromise harder.
    • Keep firmware and drivers updated to avoid compatibility issues with code integrity enforcement.

Networking and Remote Access protections

Server 2016 strengthens network-level protections and remote administration.

  • SMB improvements

    • SMB 3.x enhancements include encryption for SMB sessions, improving confidentiality for file shares without needing IPsec.
    • Use SMB encryption for sensitive file shares (per-share or per-server).

  • Remote Desktop (RDP)

    • Support for restricted admin mode, Remote Credential Guard, and Network Level Authentication (NLA) helps reduce exposure of credentials and unauthenticated sessions.
    • Use RD Gateway and limit RDP exposure to the internet; require MFA where possible.

  • IP Address Management & firewall

    • Use Windows Firewall with advanced security and IPsec for segmenting server communications.
    • Segment management networks from user networks and use bastion/jump boxes for administrative access.

Auditing, logging, and advanced threat detection

Visibility is essential to detect and respond to attacks.

  • Advanced auditing

    • Use Group Policy to enable advanced auditing policies for process creation, privilege use, authentication events, and object access.
    • Enable PowerShell script block logging and Module logging to see script-based activity (important for detecting lateral movement and attacks that use PowerShell).

  • Event forwarding and SIEM

    • Forward events to a central SIEM or event collector. Correlate logs for suspicious patterns (credential use, privilege escalations, atypical logins).
    • Use Sysmon for richer process and network logging on critical servers.

  • Integration with Windows Defender Advanced Threat Protection (ATP)

    • Although full ATP capabilities evolved beyond Server 2016’s initial release, integrating Server 2016 workloads with endpoint detection and response (EDR) systems provides behavioral detection, hunting, and remediation.

Operational tips:

  • Prioritize logging of authentication, privilege changes, and remote sessions for servers running critical apps.
  • Retain logs long enough to investigate multi-stage intrusions.

Patch management and configuration baseline

No security stack is complete without timely patching and consistent configuration.

  • Patch management

    • Use WSUS, System Center Configuration Manager (SCCM), or other patch management tools to keep servers updated.
    • Test updates in a staging environment to reduce risk of incompatibility.

  • Configuration baselines

    • Use Desired State Configuration (DSC) or Group Policy to enforce secure configurations and prevent drift.
    • Apply CIS Benchmarks or Microsoft security baselines as starting points and tailor to your environment.

Practical deployment checklist (concise)

  • Enable Secure Boot and UEFI where supported.
  • Assess drivers and applications for HVCI/Device Guard compatibility; pilot in audit mode.
  • Enable Credential Guard on domain-joined servers where credential theft risk is high.
  • Deploy Windows Defender or a managed AV solution and enable real-time protection.
  • Harden exposed services; minimize installed server roles and open ports.
  • Implement JEA endpoints for delegated administration.
  • Use shielded VMs and HGS for multi-tenant or high-confidentiality workloads.
  • Centralize logging to a SIEM and enable advanced auditing (PowerShell logging, process creation).
  • Use SMB encryption for sensitive file shares; limit RDP exposure and enable Remote Credential Guard/NLA.
  • Maintain regular patching, firmware updates, and configuration baselines (DSC/GPO).

Limitations and compatibility considerations

  • Some features (Credential Guard, Device Guard, Shielded VMs) require specific hardware/firmware: UEFI, TPM 2.0 (for some scenarios), Secure Boot, and Hyper-V support.
  • HVCI/Device Guard may block older kernel drivers and need vendor-signed drivers or whitelisting.
  • Shielded VMs and HGS add operational complexity and require planning for attestation, key management, and recovery.
  • Security features reduce risk but do not eliminate it; they must be combined with good operational practices and monitoring.

Conclusion

Windows Server 2016 represents a major step forward in platform security by integrating virtualization-based protections, improved credential protections, container and VM isolation, and stronger code integrity enforcement. Successful deployment requires planning: verify hardware and driver compatibility, pilot features in audit mode, centralize logging and monitoring, and combine technical controls with least-privilege operational practices. When properly implemented, these enhancements substantially raise the bar for attackers seeking to compromise server infrastructure.

Comments

Leave a Reply

Your email address will not be published. Required fields are marked *

More posts