The most prevalent method to subvert HVCI environments does not bypass the hypervisor itself, but rather abuses the trust chain. In a BYOVD attack, an attacker with administrative privileges installs a legitimately signed, legacy, or third-party driver known to contain an arbitrary memory read/write vulnerability (e.g., outdated anti-cheat drivers or hardware utilities).
Hypervisor-Protected Code Integrity (HVCI), also known as Memory Integrity, is a critical Windows security feature that uses hardware virtualization to protect the kernel from malicious code. By ensuring that only signed, validated code can run in kernel mode, it serves as a formidable barrier against rootkits and advanced persistent threats. However, security researchers have identified specific techniques and vulnerabilities that can circumvent these protections. The Role of HVCI in Windows Security
Where the standard Windows kernel ( ntoskrnl.exe ), user-mode applications, and third-party drivers execute.
This is a attack.
Over the years, researchers have cataloged several families of HVCI bypasses. They generally fall into two high-level categories: (exploiting design flaws) and Operational Bypasses (exploiting implementation or race conditions). Hvci Bypass
Hypervisor-Protected Code Integrity (HVCI), also known as Memory Integrity, is a cornerstone of modern Windows virtualization-based security (VBS). By leveraging the Type-1 Microsoft Hyper-V hypervisor, HVCI creates an isolated, highly secure environment that enforces strict code integrity policies. Its primary objective is simple yet absolute: ensure that only signed, trusted code can execute in kernel mode (Ring 0).
Understanding HVCI Bypasses: Architecture, Mitigation, and Exploitation Vectors
An isolated environment running a minimal "Secure Kernel" ( securekernel.exe ) and isolated user-mode applications (Trustlets). HVCI lives inside VTL 1. Second-Level Address Translation (SLAT)
). Kernel memory pages are either writable or executable, never both at the same time. This prevents attackers from writing malicious code to a memory page and then executing it. The most prevalent method to subvert HVCI environments
The Windows hypervisor splits the system into two primary execution environments:
Hyper-Virtualization-Based Code Integrity (HVCI), commonly known as Memory Integrity in Windows, represents one of Microsoft’s most robust modern security boundaries. By leveraging hardware virtualization, HVCI ensures that only digitally signed, trusted code can execute within the Windows kernel. However, as defensive boundaries harden, offensive researchers and malware developers aggressively seek methods to circumvent them.
HVCI operates entirely within VTL 1. It utilizes Second-Level Address Translation (SLAT)—implemented via Extended Page Tables (EPT) on Intel or Nested Page Tables (NPT) on AMD—to enforce page-level permissions across the system.
Are you developing a driver and need to ensure ? Share public link By ensuring that only signed, validated code can
While designed to block malware, it has become a hot topic in the gaming community—particularly for Valorant players—because anti-cheat systems like Riot Vanguard often require it to be active to ensure a "clean" environment. ⚡ Why Do Users "Bypass" HVCI?
The complexity of VBS and HVCI requires attackers to think beyond traditional kernel patching. Several distinct methodologies have emerged to dismantle this hypervisor-level protection:
Contains standard user-mode applications and the standard Windows kernel.