A friend of mine asked me this recently, and besides the obvious "try with antivirus vendors" I didn't know what to answer.
He's been building a pretty large collection of data from a honeynet consisting of multiple nodes running Cowrie, Dionaea, Glastopf, Honeytrap and others, spread over multiple IPs in different geographical areas.
He's been gathering this data for the past year, while researching neural nets and a way to "learn" from what he gathers, but he realized that this project is taking longer than expected, and wants to possibly off-load some of the data to help pay for the research.
Besides the obvious antivirus companies, where could he look for entities interested in this type of data? Are there any broker-type entities out there? Where would you go looking?