Did you try to communicate with the user who sends this offer to you?
No, should I?
not because there is no point. you certainly can't even contact him because it is a short-term created account just to invite some users and go on. Which real business operate in that way.
Also, if it is a scam, is there anything that can be done to get it shut down at the very least? Where can I report it? Would legal action bring any sort of results?
No, you can't do almost anything to stop fraud like this. just spread the word and warn others of this scam. Some people will say, you can report them to his domain register, Namecheap in this case
https://who.is/whois/winxtrade.comprobably sending email to
abuse@namecheap.com