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Updated on August 14, 2025
Virtualization-based Security (VBS) uses hardware-backed hypervisor technology to create an isolated security environment called Virtual Secure Mode (VSM). This protected memory region operates separately from the main operating system, ensuring critical components are secure even if the OS is compromised. By addressing the risk of kernel-level attacks, VBS establishes a hardware-enforced boundary to safeguard essential security functions.
Definition and Core Concepts
VBS operates through several foundational technologies that work together to create a secure computing environment.
The hypervisor serves as a thin layer of software positioned between the hardware and the operating system. Unlike traditional hypervisors used for server virtualization, the VBS hypervisor focuses specifically on security isolation rather than resource allocation across multiple operating systems.
Hardware virtualization provides the essential CPU features that make VBS possible. Intel VT-x and AMD-V virtualization extensions allow a single physical processor to create multiple isolated execution environments. These hardware features ensure that the hypervisor maintains control over memory access and execution privileges.
The isolated virtual environment represents the core security boundary in VBS. This protected memory space, known as VSM, cannot be accessed by code running in the normal Windows kernel or user mode. The hardware enforces this isolation, making it immune to software-based attacks.
The kernel, which traditionally holds the highest privileges in an operating system, becomes a less trusted component under VBS. Critical security functions are moved out of the kernel and into the protected VSM, reducing the attack surface available to malware that achieves kernel-level access.
How VBS Works
VBS protection begins during the system boot process and maintains security boundaries throughout operation.
During hypervisor loading, the Windows hypervisor initializes before the main operating system starts. This early loading ensures that the hypervisor establishes control over the hardware before any potentially compromised software can execute. The hypervisor configures hardware features like Second-Level Address Translation (SLAT) to enforce memory isolation.
The isolated environment creation phase establishes the VSM as a separate memory region. The hypervisor configures page tables and memory management units to prevent normal Windows kernel code from accessing VSM memory. This hardware-enforced separation creates an impenetrable boundary between trusted and untrusted code.
Security solutions deployment moves critical Windows security components into the protected VSM. Features like Credential Guard and Hypervisor-Enforced Code Integrity (HVCI) operate within this isolated environment, where they can perform security functions without interference from malware.
The protection mechanism actively blocks any attempts to access or manipulate security components running in VSM. When malware tries to dump credentials or modify kernel code integrity checks, the hypervisor intercepts these attempts and prevents them from succeeding. This protection remains effective even if attackers gain full control over the Windows kernel.
Key Features and Components
VBS implements several specific security features that demonstrate its protective capabilities.
Credential Guard represents one of the most significant VBS features for enterprise security. This component isolates domain credentials, NTLM password hashes, and Kerberos tickets within the VSM. Traditional credential-dumping tools like Mimikatz cannot access these protected credentials, effectively neutralizing pass-the-hash attacks and similar credential theft techniques.
Hypervisor-Enforced Code Integrity (HVCI) ensures that only digitally signed, trusted code can execute in kernel mode. HVCI runs within the VSM and validates all kernel-mode drivers before they load. This prevents unsigned malware from gaining kernel privileges and stops sophisticated rootkits that rely on loading malicious drivers.
Hardware dependency requirements make VBS unavailable on older systems but ensure strong security foundations on supported platforms. VBS requires a 64-bit processor with virtualization extensions, SLAT support for efficient memory management, and TPM 2.0 for secure key storage and attestation.
The defense-in-depth approach positions VBS as an additional security layer rather than a replacement for existing protections. VBS works alongside traditional antivirus, firewalls, and other security tools to create a more comprehensive security posture.
Use Cases and Applications
VBS deployment spans multiple scenarios where kernel-level protection is essential.
Windows 10 and Windows 11 systems implement VBS as a default security feature on compatible hardware. Windows Server environments use VBS to protect critical domain controllers and high-value servers from advanced attacks. Microsoft automatically enables VBS on new Windows 11 installations that meet hardware requirements.
Endpoint protection scenarios benefit significantly from VBS implementation. Organizations facing advanced persistent threats use VBS to protect endpoints that may be targeted by nation-state actors or sophisticated cybercriminal groups. The technology proves particularly valuable for protecting systems that process sensitive data or have elevated network privileges.
Zero Trust security models rely on VBS as a fundamental component. The technology aligns with Zero Trust principles by assuming that the traditional security perimeter has been breached and that even the operating system kernel may be compromised. VBS provides the hardware-backed trust boundary that Zero Trust architectures require.
Advantages and Trade-offs
VBS implementation involves clear benefits and specific limitations that organizations must consider.
The stronger security provided by VBS creates protection against previously unstoppable attacks. Kernel rootkits that could bypass traditional security measures cannot penetrate the hardware-enforced VSM boundary. Credential theft attacks that have plagued enterprises for years become ineffective against Credential Guard protection.
Resilience represents a key VBS advantage in that critical security assets remain protected even during a complete operating system compromise. Attackers who gain full administrative privileges and kernel access still cannot access credentials or disable code integrity checks running in the VSM.
The reduced attack surface eliminates entire categories of vulnerabilities. By moving security-critical functions into the isolated VSM, VBS removes these components from the much larger attack surface of the normal Windows kernel.
Hardware requirements limit VBS deployment to newer systems with specific capabilities. Organizations with older hardware cannot implement VBS protection, creating potential security gaps in mixed environments. The requirement for TPM 2.0 specifically excludes many systems that lack this hardware security module.
Performance overhead affects some specialized workloads, particularly those involving extensive virtualization or real-time processing. While most business applications experience minimal impact, high-performance computing environments may observe measurable performance degradation.
Troubleshooting and Considerations
VBS implementation requires attention to hardware configuration and software compatibility.
BIOS and UEFI settings must enable hardware virtualization features for VBS to function. Intel VT-x or AMD-V extensions must be activated, and SLAT must be available and enabled. Some systems ship with these features disabled by default, requiring manual BIOS configuration.
Compatibility issues can arise with older drivers that lack proper code signing or that attempt to modify kernel structures in ways that HVCI prevents. Organizations must audit their driver landscape and update or replace incompatible components before enabling VBS features.
VBS enabling varies by Windows version and system configuration. Windows 11 enables VBS by default on compatible systems, while Windows 10 installations may require manual configuration through Group Policy or registry settings. Enterprise environments typically manage VBS deployment through centralized management tools.
Credential theft protection through Credential Guard requires domain-joined systems and specific configuration steps. Organizations must understand the differences between credential protection modes and configure appropriate policies for their security requirements.
Key Terms Appendix
- Hypervisor: A virtual machine monitor that provides hardware abstraction and isolation services for VBS security features.
- Credential Guard: A VBS feature that isolates domain credentials and authentication tokens within the protected VSM environment.
- Hypervisor-Enforced Code Integrity (HVCI): A VBS security mechanism that ensures only digitally signed code can execute in kernel mode.
- Kernel: The core component of the Windows operating system that manages system resources and provides services to applications.
- TPM (Trusted Platform Module): A hardware-based security module that provides cryptographic functions and secure key storage for VBS operations.
- Virtual Secure Mode (VSM): The isolated memory region created by the VBS hypervisor where security-critical components execute safely.
- Second-Level Address Translation (SLAT): A hardware feature that enables efficient memory virtualization and isolation in VBS environments.
