Use cloudflare, I do and for $20 US a month its great. blocks tens of thousands of malicious and spammer ips per month with no config.
what happens is that as you get their ips blocked with clourflare the hackers/spammers after a while stop trying because that ip will be blocked across the entire cloudflare network. My first month had over 100,000 firewall hits, mostly china. The past 30 days I have only seen about 12, 000 hits.
www.cloudflare.com