SSHGuard/sshguard

Daemon to ban hosts that cause multiple authentication errors

SSH tarpit that slowly sends an endless banner

A lightweight, real time log monitoring tool designed to detect and block IP addresses exhibiting abusive behavior such as brute force attacks, excessive requests, or suspicious patterns. Automatically integrates with your server’s firewall (iptables or ufw) to block offenders and protect web services without relying on external services.

The NetWatch SSH-AttackPod is a modified OpenSSH server that records any attempted username/password combinations along with the source IP and reports it to the NetWatch back end

Anti-Abuse for servers at authentication time

🧱 Ban subnets using Windows Firewall rules after they make enough incorrect login attempts, as indicated by Windows Event Log records.

Поставь звёздочку если использовал, а то палец откушу

This script helps to avoid portscanning on Linux systems.