Windows Virtualization-Based Security (VBS) is a security feature in Windows that uses hardware virtualization to create and isolate a secure region of memory from the normal operating system. This secure memory region can be used to host various security solutions, providing protection from vulnerabilities and attacks that could compromise the system.
Key Components and Features of VBS:
- Hypervisor-Enforced Code Integrity (HVCI):
- Ensures that only signed and verified code can execute in kernel mode.
- Uses the hypervisor to enforce code integrity policies, preventing unsigned drivers or system files from being loaded.
- Credential Guard:
- Isolates and protects credentials such as NTLM hashes and Kerberos tickets using VBS.
- Prevents attackers from stealing credentials even if the operating system kernel is compromised.
- Device Guard:
- Combines HVCI with other features to ensure that the device runs only trusted applications.
- Includes Configurable Code Integrity (CCI) and relies on policies that define which code can be trusted.
- Secure Kernel Mode:
- Runs alongside the normal Windows kernel, but is isolated from it.
- Protects key processes and data from being tampered with or read by the normal operating system.
- Kernel Data Protection (KDP):
- Prevents kernel memory from being tampered with by malicious actors.
- Protects non-executable data in the kernel such as data structures, which are vital for the operating system’s security and stability.
How VBS Works:
- Hardware Requirements:
- Requires modern CPUs with virtualization extensions (such as Intel VT-x or AMD-V).
- Requires a system firmware that supports Secure Boot and UEFI.
- Typically requires TPM 2.0 for certain features like Credential Guard.
- Operational Flow:
- At system boot, the Windows hypervisor (Hyper-V) initializes and creates an isolated environment.
- The VBS components operate within this environment, isolated from the main operating system and its potential vulnerabilities.
- This isolation ensures that even if the main operating system is compromised, the VBS-protected components remain secure.
Benefits of VBS:
- Enhanced Security:
- Protects against a variety of modern threats, including malware, rootkits, and credential theft.
- Provides a stronger security boundary than traditional software-based security measures.
- Trustworthy Execution Environment:
- Ensures that critical security mechanisms and sensitive data are executed and stored in a protected environment.
Use Cases:
- Enterprise Environments:
- Provides advanced protection mechanisms for organizations handling sensitive data and requiring stringent security measures.
- Helps meet compliance and regulatory requirements by providing enhanced security controls.
- Secure Workloads:
- Ideal for protecting workloads that handle sensitive or high-value data, such as financial transactions, healthcare records, and government data.
In summary, Windows VBS leverages hardware virtualization to create a secure environment that enhances the security of the operating system, providing robust protection against a wide range of threats and vulnerabilities.
