I think i have a spam infection

hoping someone can help as I have a spammer continually posting spam in my buddypress stream. i have deleted him as a user however he keeps appearing in the user database along with the same user id i deleted. i also blocked the ip with wordfence but it makes no difference, i am getting a several new spam posts every few minutes. i am guessing this is a virus. can someone advise what i can do?

thanks