BlackLotus, a UEFI bootkit that’s sold on hacking forums for about $5,000, can now bypass Secure Boot, making it the first known malware to run on Windows systems even with the firmware security feature enabled.
Secure Boot is supposed to prevent devices from running unauthorized software on Microsoft machines. But by targeting UEFI the BlackLotus malware loads before anything else in the booting process, including the operating system and any security tools that could stop it.
Kaspersky’s lead security researcher Sergey Lozhkin first saw BlackLotus being sold on cybercrime marketplaces back in October 2022 and security specialists have been taking apart piece by piece ever since.
In research published today, ESET malware analyst Martin Smolár, says the myth of an in-the-wild bootkit bypassing secure boot “is now a reality,” as opposed to the usual slew of fake ads by criminals attempting to scam their fellow miscreants.
The latest malware “is capable of running on even fully-up-to-date Windows 11 systems with UEFI Secure Boot enabled,” he added.
BlackLotus exploits a more than one-year-old vulnerability, CVE-2022-21894, to bypass the secure boot process and establish persistence. Microsoft fixed this CVE in January 2022, but miscreants can still exploit it because the affected signed binaries have not been added to the UEFI revocation list, Smolár noted.
“BlackLotus takes advantage of this, bringing its own copies of legitimate – but vulnerable – binaries to the system in order to exploit the vulnerability,” he wrote.
Plus, a proof-of-concept exploit for this vulnerability