I don't know about malwares but online gaming cheat developers have been using a signed driver from Intel that has a vulnerability allowing to load any unsigned driver. Despite the exploit being discovered back in 2016, the driver certificate is still valid as of today and works with Windows 11.
https://nvd.nist.gov/vuln/detail/CVE-2015-2291
https://github.com/TheCruZ/kdmapper