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What is the security system on Windows 11?

Fannie S Lott
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Windows 11 has advanced hardware security. But, how?

Topic starter Posted : 15/08/2021 6:25 pm
Sadie M Rice
New Member

Feature 1: TPM 2.0 and Secure Boot

Trusted Platform Module (TPM) is a technology designed to provide hardware-based, security-related cryptographic functions. If you have a PC that was manufactured within the last five years, chances are, you have a TPM chip on your motherboard that supports version 2.0. You can determine this by opening up Device Manager and expanding "Security devices." If it says "Trusted Platform Module 2.0," you're good to go.

This is shown as "Security Processor" in the Device Security Settings menu in Windows 10 (and Windows 11). 

So what does TPM actually do? It is used to generate and store cryptographic keys unique to your system, including an RSA encryption key unique to your system's TPM itself. In addition to being used traditionally with smart cards and VPNs, TPMs are used to support the Secure Boot process. It measures the integrity of the boot code of the OS, including the firmware and individual operating system components, to make sure they haven't been compromised.

There's nothing you need to do to make it work; it just does, provided it is not disabled in your UEFI. Your organization can choose to deploy Secure Boot on Windows 10 via Group Policy or an enterprise MDM-based solution such as Microsoft Endpoint Manager.

While most manufacturers ship their PCs with TPM turned on, some may have it disabled, so if it doesn't show up in Device Manager or shows it as disabled, boot up into your UEFI firmware settings and look. 

If the TPM has never been prepared for use on your system, simply invoke the utility by running tpm.msc from the command line.

Feature 2: Virtualization-Based Security (VBS) and HVCI

While TPM 2.0 has been common in many PCs for as long as six years, the feature that really makes the security rubber hit the road in Windows 10 and Windows 11 is HVCI or Hypervisor-Protected Code Integrity, also referred to as Memory Integrity or Core Isolation, as it appears in the Windows Device Security menu. 

While it is required by Windows 11, you need to turn it on manually in Windows 10. Simply click on "Core Isolation Details" and then turn on Memory Integrity with the toggle switch. It may take about a minute for your system to turn it on, as it needs to check every memory page in Windows before enabling it.

This feature is only usable on 64-bit CPUs with hardware-based virtualization extensions, such as Intel's VT-X and AMD-V.  While initially implemented in server-class chips as far back as 2005, they have been present in almost all desktop systems since at least 2015, or Intel Generation 6 (Skylake). However, it also requires Second Level Address Translation (SLAT), which is present in Intel's VT-X2 with Extended Page Tables (EPT) and AMD's Rapid Virtualization Indexing (RVI).

There's an additional HVCI requirement that any I/O devices capable of Direct Memory Access (DMA) sit behind an IOMMU (Input-Output Memory Management Unit). Those are implemented in processors that support Intel VT-D, or AMD-Vi instructions

It sounds like a long list of requirements, but the bottom line is that you are good to go if Device Security says these features are present in your system.

Isn't virtualization mainly used to improve workload density in datacenter servers or by software developers to isolate their testing setup on their desktops or run foreign OSes such as Linux? Yes, but virtualization and containerization/sandboxing are now increasingly used to provide additional security layers in modern operating systems, including Windows.

In Windows 10 and Windows 11, VBS, or Virtualization-based Security, uses Microsoft's Hyper-V to create and isolate a secure memory region from the OS. This protected region is used to run several security solutions that can protect legacy vulnerabilities in the operating system (such as from unmodernized application code) and stop exploits that attempt to defeat those protections.  

HVCI uses VBS to strengthen code integrity policy enforcement by checking all kernel-mode drivers and binaries before starting and preventing unsigned drivers and system files from being loaded into system memory. These restrictions protect vital OS resources and security assets such as user credentials -- so even if malware gets access to the kernel, the extent of an exploit can be limited and contained because the hypervisor can prevent the malware from executing code or accessing secrets. 

VBS performs similar functions for application code as well -- it checks apps before they are loaded and only starts them if they are from approved code signers, doing this by assigning permissions across every page of system memory. All of this is performed in a secure memory region, which provides more robust protections against kernel viruses and malware.

Think of VBS as Windows' new code enforcement officer, your kernel and app Robocop that lives in a protected memory box that is enabled by your virtualization-enabled CPU.

Feature 3: Microsoft Defender Application Guard (MDAG)

One particular feature that many Windows users are not familiar with is Microsoft Defender Application Guard, or (MDAG). 

This is another virtualization-based technology (also known as "Krypton" Hyper-V containers) that, when combined with the latest Microsoft Edge (and current versions of Chrome and Firefox using an extension), creates an isolated memory instance of your browser, preventing your system and your enterprise data from being compromised by untrusted websites.

Should the browser become infected by scripting or malware attacks, the Hyper-V container, which runs separately from the host operating system, is kept isolated from your critical systems processes and your enterprise data.

MDAG is combined with Network Isolation settings configured for your environment to define your private network boundaries as defined by your enterprise's Group Policy.

In addition to protecting your browser sessions, MDAG can also be used with Microsoft 365 and Office to prevent Word, PowerPoint, and Excel files from accessing trusted resources such as enterprise credentials and data. This feature was released as part of a Public Preview in August of 2020 for Microsoft 365 E5 customers.

MDAG, which is part of Windows 10 Professional, Enterprise, and Educational SKUs, is enabled with the Windows Features menu or a simple PowerShell command; it doesn't require Hyper-V to be turned on.

While MDAG primarily targets enterprises, end-users and small businesses can turn it on with a simple script that sets the Group Policy Objects. This excellent video and accompanying article published at URTech.Ca covers the process in greater detail.

Posted : 15/08/2021 6:31 pm