VBS leverages hardware virtualization extensions (Intel VT-x or AMD-V) to split the operating system into distinct security domains called .
The field of HVCI bypass continues to evolve rapidly. Recent developments suggest several emerging trends:
For instance, an attacker can traverse the active process list ( ActiveProcessLinks ) and overwrite the Token structure of a low-privileged process with the Token of the System process (PID 4). The process inherits system-level permissions entirely through data modification, completely circumventing HVCI restrictions. 4. Exploiting Vulnerable VTL 1 Interfaces Hvci Bypass
: A new Windows rootkit bypasses HVCI and PatchGuard by hiding processes using a critical timing window. The technique uses a legitimate Microsoft API, PsSetCreateProcessNotifyRoutineEx, to get notified when a process terminates. Inside the callback, the corrupted LIST_ENTRY structures are repaired microseconds before the kernel's own integrity checks run. The result is that the process terminates cleanly with no crash and no detection. This technique bypasses both HVCI and PatchGuard while operating entirely within documented APIs.
Because the driver is legitimately signed, HVCI validates it and allows it to load. The attacker then leverages the driver’s internal flaws to manipulate kernel structures, manipulate data parameters, or hijack existing, legitimate execution flows already approved by HVCI. Vector B: Data-Only Attacks (DKOM) older driver (e.g.
While you can write to memory, HVCI still prevents you from marking that memory as Executable . To bypass HVCI here, you must find a way to redirect existing authorized code execution to your own data (ROP chains). 2. Data-Only Attacks
Traditional Code Integrity (CI) (e.g., Kernel Mode Code Signing – KMCS) checks that any code loaded into the kernel is signed by a trusted authority. However, once loaded, that code can still be modified at runtime. A classic exploit would: manipulate data parameters
Second-Level Address Translation (SLAT) & Extended Page Tables (EPT)
A highly stripped-down, isolated "Secure Kernel" dedicated to running critical security operations. The Enforcement Link: KMCI and SLAT
An attacker drops a legitimately signed, older driver (e.g., anti-cheat drivers, hardware monitoring tools) that contains a known vulnerability exposing arbitrary physical or virtual memory read/write primitives.