Intel BootGuard private keys leaked after MSI hack, report
MSI devices equipped with 11th gen Tiger Lake, 12th gen Adler Lake and 13th gen Raptor Lake CPUs could be affected, says researcher
Intel is currently investigating the alleged leakage of BootGuard private keys intended to safeguard PCs against the covert introduction of malware.
The incident is believed to have occurred when data that belonged to Taiwanese computer hardware manufacturer Micro-Star International (MSI) was stolen and subsequently dumped online.
In March, the Money Message extortion group targeted MSI, claiming to have obtained 1.5TB of data that included source code, private keys, firmware and databases.
The ransomware gang demanded a payment of $4 million from the company and threatened to publicly release the stolen data if the demand was not met.
MSI confirmed the cyberattack in a filing with the Taiwan Stock Exchange last month.
Recently, the perpetrators started releasing the stolen data, which included the source code for motherboard firmware developed by MSI.
Alex Matrosov, the founder and CEO of cybersecurity firm Binarly, tweeted on Friday about the online leak of an OEM private key associated with Intel's BootGuard security feature. Matrosov said the incident has had a significant impact on the entire ecosystem.
He cautioned that the leaked source code includes image signing private keys for 57 MSI products and Intel Boot Guard private keys for 116 MSI products.
"Intel is aware of these reports and actively investigating. There have been researcher claims that private signing keys are included in the data including MSI OEM Signing Keys for Intel BootGuard," Intel told BleepingComputer.
"It should be noted that Intel BootGuard OEM keys are generated by the system manufacturer, and these are not Intel signing keys."
Boot Guard is a cryptographic technology created to safeguard PCs against the execution of counterfeit UEFI firmware or a modified BIOS.
As per an Intel white paper, the "policies of Intel BootGuard are rooted in Field Programmable Fuses, making them unalterable for the lifetime of a platform. Once provisioned, Intel Boot Guard cannot be disabled, and provisioned policies cannot be spoofed."
PCs that utilise Intel chips and BootGuard protection, once enabled and configured, will typically only operate firmware if it is digitally signed using keys similar to those that were leaked from MSI.
The firmware's role is to initiate the OS, fulfilling the requirements of Windows Secure Boot.
If the firmware is not correctly digitally signed, it may indicate that an individual has attempted to tamper with the code to introduce unauthorised spyware below the OS, evading the detection of antivirus and other security tools.
An unauthorised person with access to the private BootGuard keys can utilise them to sign their malicious code. This would make the malware appear trustworthy whereupon it could be executed on MSI hardware, instead of being blocked.
So, the leakage of these keys impairs the ability of MSI computers to leverage Intel's BootGuard for blocking malicious firmware. This scenario represents a significant security concern.
If malicious actors are successful in circumventing the BootGuard technology, they could attain complete system access, steal sensitive information and carry out various illicit activities without arousing suspicion.
This is because their malware would operate below the OS and antivirus programs, making it extremely challenging to detect.
Matrosov suggested that the leak of these keys could have impaired the effectiveness of Intel BootGuard on MSI devices equipped with "11th Tiger Lake, 12th Adler Lake, and 13th Raptor Lake" CPUs.
"Our investigation is ongoing, stay tuned for updates," he added.