The person or organization behind the hack remains unknown.
Source: Tom’s Hardware
We recently broke the news that Intel's Alder Lake BIOS source code had been leaked to 4chan and Github, with the 6GB file containing tools and code for building and optimizing BIOS/UEFI images. We reported the leak within hours of the initial occurrence, so we didn't yet have confirmation from Intel that the leak was genuine. Intel has now issued a statement to Tom's Hardware confirming the incident:
"Our proprietary UEFI code appears to have been leaked by a third party. We do not believe this exposes any new security vulnerabilities as we do not rely on obfuscation of information as a security measure. This code is covered under our bug bounty program within the Project Circuit Breaker campaign, and we encourage any researchers who may identify potential vulnerabilities to bring them our attention through this program. We are reaching out to both customers and the security research community to keep them informed of this situation." — Intel spokesperson.
The BIOS/UEFI of a computer initializes the hardware before the operating system has loaded. Among its many responsibilities, the BIOS establishes connections to certain security mechanisms, like the TPM (Trusted Platform Module). Now that the BIOS/UEFI code is in the wild and Intel has confirmed it as legitimate, both nefarious actors and security researchers alike will undoubtedly probe it to search for potential backdoors and security vulnerabilities.
Source: Tom’s Hardware