Researchers from firmware security firm Eclypsium have discovered a potential backdoor-like behavior in Gigabyte systems, which exposes devices to compromise. The firmware in Gigabyte systems executes a Windows native executable during startup, enabling insecure downloading and execution of additional payloads.
This behavior, similar to other backdoor features, poses a significant supply chain risk and requires a firmware update for complete removal. Eclypsium is collaborating with Gigabyte to address the issue and recommends scanning systems, updating firmware, and taking precautions to minimize the risk.
Further analysis revealed that this suspicious behavior is present in hundreds of models of Gigabyte PCs. The researchers identified a Windows Native Binary executable file within the impacted UEFI firmware, which is written to disk during the system boot process. This technique is commonly used by UEFI implants and backdoors, and the executable can carry out malicious activities such as downloading and executing additional payloads.
The use of HTTP protocols exposes devices to machine-in-the-middle attacks, while even when using HTTPS, the validation of the remote server certificate is not implemented correctly, allowing for potential MITM attacks.
Compounding the issue, the firmware lacks support for digital signature verification, making it easier for threat actors to persistently infect vulnerable systems. The backdoor-like behavior discovered in Gigabyte systems presents several attack scenarios, including abuse by threat actors, compromise of the OEM update infrastructure and supply chain, persistence using UEFI rootkits and implants, and MITM attacks on firmware and software update features.
Eclypsium recommends scanning and monitoring systems, updating to the latest validated firmware and software, disabling the affected feature in UEFI/BIOS setup, setting a BIOS password, and blocking the URLs associated with the suspicious behavior.
Eclypsium is actively working with Gigabyte to address the issue and mitigate the potential risks posed by this backdoor-like behavior. It highlights the importance of regularly updating firmware and taking necessary security precautions to protect against supply chain risks. By addressing this vulnerability, organizations can minimize the potential for compromise and unauthorized access to their systems.
