The best alternatives to Modshield SB are DigitalOcean, CrowdSec, and Farewill. If these 3 options don't work for you, we've listed a few more alternatives below.
An open-source, free and collaborative security engine. Protect your IT assets and sites from all kinds of cyber attacks. Share malevolent IPs with fellow users and protect them too. Have each other’s backs. Make the Internet safer, together.