An MMORPG with cute anime-style characters and maybe a bit too much inspiration taken from another classic Nintento franchise, Genshin Impact is a relatively popular game across the PlayStation, iOS, Android, and PC platforms. That last one has already generated a bit of controversy, since the PC version game includes an anti-cheat kernel driver that runs in the Windows kernel context, and on initial release that module kept running even after the game was closed.
That anti-cheat driver is back in the news, with Trend Micro discovering a ransomware campaign that includes
mhyprot2.sys, the anti-cheat driver, as a component of the infection. The module is known to have vulnerabilities, and is still a signed kernel driver, so the malware campaign loads the driver and uses its functions to disable anti-malware protections.
The rest of the campaign is straightforward. Starting with access to a single domain-connected machine, an attacker uses that foothold to gain access to the domain controller. The malicious script is hosted on shared storage, and PsExec is used to run it on all the domain member machines. The real novelty here is the use of the vulnerable anti-cheat kernel driver as the anti-malware bypass. As far as we can tell, this driver is *still* signed and considered trustworthy by Windows. We join the call to Microsoft, to revoke this vulnerable driver, as it’s now actively being used in ongoing malware campaigns. For more on security, check out our weekly column on the topic,