- You say you suspect a virus, but you don't tell why.
- You're rather mysterious when you say "20 Jan 2016, was last day computer was protected from an attack previously resolved end Dec. 2015." What does that mean?
- You have no virus protection now. So apparently you had and you uninstalled it. What did you have and why did you uninstall it?
- What are "these two"?
- You want to clean up something, but what is that something?

Usually, if you have a virus and your own antivirus doesn't remove it and the usual CD-based antivirus (do those exist for a Mac?) doesn't either, or after removing it the system is dysfunctional, then you reinstall the OS from scratch (after backing up everything you don't want to lose).

Kees