Ransomware operators targeting Windows servers to deploy Magniber ransomware payloads. PrintNightmare is a class of security vulnerabilities (tracked as CVE-2021-1675) impacting the Windows Print Spooler service, Windows print drivers, and the Windows Point and Print feature. Microsoft has released security updates to address these vulnerabilities in June, July, and August. Microsoft also published a security advisory on Wednesday providing a workaround for a zero-day bug allowing privilege escalation, with no patch available.
Source: https://www.bleepingcomputer.com/news/security/ransomware-gang-uses-printnightmare-to-breach-windows-servers/