The attack campaigns appear to be exploiting CVE-2021-21974 for which a patch has been available since February 23, 2021. Systems running ESXi versions 7.0, 6.7 and 6.5 are currently being targeted and pose the greatest threat.
The OpenSSL V3 Vulnerabilities project announced details of vulnerabilities that exist in versions of the OpenSSL software versions earlier than version 3.0.7. They have released OpenSSL Version 3.0.7 to address these security vulnerabilities. BigFix can address and speed vulnerability remediation.