Unsigned firmware in various system components such as WiFi adapters, USB hubs, trackpads, and cameras used in Lenovo, Dell, HP and other major manufacturers. The flaws existing in these components allowed the attackers to compromise millions of Windows and Linux systems, and exfiltrate the data, disrupt the operation also implant the malware. The primary issue in the flaw is that many of the peripheral devices do not verify that firmware is properly signed with a high-quality public/private key before running the code.”]
Source: https://gbhackers.com/unsigned-firmware-in-laptop-severs/