This malware attacks your website, then converts your electric bill and CPU cycles directly into cash. Secure web hosting is a full-time job. It’s constant learning curve adapting to new attacks. From the article at wordfence.com:
To summarize, the attacker is leveraging sophisticated malware to control compromised WordPress servers remotely. The servers are being used to both attack other WordPress sites and to mine for Monero, a cryptocurrency that can be efficiently mined using web server hardware. We discovered evidence showing that the attacker has earned almost $100,000 from mining already, and likely quite a lot more.