Adversaries may modify component firmware to persist on systems. Some adversaries may employ sophisticated means to compromise computer components and install malicious firmware that will execute adversary code outside of the operating system and main system firmware or BIOS. This technique may be similar to System Firmware but conducted upon other system components/devices that may not have the same capability or level of integrity checking.
Malicious component firmware could provide both a persistent level of access to systems despite potential typical failures to maintain access and hard disk re-images, as well as a way to evade host software-based defenses and integrity checks.
View in MITRE ATT&CK®| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| intel-ptt | Intel Platform Trust Technology | Win 11, Secure Boot | T1542.002 | Component Firmware |
Comments
Windows Secure Boot leverages Intel PTT (TPM) to safeguard settings stored in UEFI, while Intel Boot Guard prevents unauthorized modifications to UEFI firmware. It verifies the signatures of the UEFI firmware, bootloader, and boot drivers before loading the operating system.
When the PC starts, the firmware checks the signature of each piece of boot software, including Unified Extensible Firmware Interface (UEFI) firmware drivers (also known as Option ROMs), Extensible Firmware Interface (EFI) applications, and the operating system. If the signatures are valid, the PC boots, and the firmware gives control to the operating system. Rollback protection also prevents the system from rolling back to older versions of firmware.
Secure Boot employs Intel PTT (TPM) to thwart attacks that attempt to alter the signature policy at the boot level in real-time or modify components involved in the boot process before the boot process. Intel Boot Guard ensures the integrity of the boot-level code before it is executed on the processor, preventing the system from proceeding with malicious boot code.
Secure Boot is able to address threats pre-os that change the signature of the loaded boot component.
System Guard Secure Launch uses a technology called Dynamic Root of Trust Measurement (DRTM). It leverages Intel PTT (TPM) and TXT to provide secure methods to boot a system and verify the integrity of the operating system and loading mechanisms. System Guard Secure Launch ensures that the system can freely boot into untrusted code initially, but shortly after launches the system into a trusted state by taking control of all CPUs and forcing them down a well-known and measured code path. This has the benefit of allowing untrusted early code to boot the system but then being able to securely transition into a trusted and measured state. The ability to transition in real-time to a secure state justified the score of significant for this feature and its corresponding protection (E.g., bootkit, rootkit, firmware corruption, etc.).
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