https://www.redhat.com/en/blog/3-antimalware-solutions
In this article, you'll learn how to install and run three different antimalware applications that can help you keep your system free of malicious irritants that make users call you at the least convenient times: chkrootkit, rkhunter, and ClamAV.
https://www.shsu.edu/intranet/policies/information_technology_policies/documents/IT-24%20Malicious%20Code%20(v1.02).pdf
This sample policy from Sam Houston State University is an example of a policy to reduce risk by protecting against malware.
https://www.sans.org/white-papers/68/
This SANS whitepaper discusses several common practices which, when implemented together, will greatly decrease, and perhaps almost stop malware.