Downloaded a torrent of cracked software – think my Mac is now infected So I downloaded a torrent of Apple Final Cut Pro.

There was a quick pop of either Terminal or Green looking terminal. The said application (green Terminal) opened and close, opened and close, and so on for a short period of time. It looked fishy so I didn't know whether it's a virus or not. 

Can someone help me. Am I safe? Should I factory reset?
You are not safe. Your personal documents, contacts, and private information are at risk. 

The behaviour you are seeing is not part of Apple's Final Cut Pro. The odd terminal like behaviour suggests you do have a rogue process or application on your Mac.

Search for a guide about how to remove malware and viruses from your Mac.