Fail2ban - Intrusion prevention framework
SSHGuard - SSHGuard monitors services through their logging activity.
RdpGuard - RdpGuard allows you to protect your Remote Desktop (RDP), POP3, FTP, SMTP, IMAP, MSSQL, MySQL, VoIP/SIP from brute-force attacks by blocking attacker's IP address. Fail2Ban for Windows.
Denyhosts - The idea of denying access to SSH servers is nothing new and I was inspired by many other scripts...
Hookem-Banem - Centralised log monitoring which distributes block requests of repeated failure attempts across...
IPBan - Block hacking attempts on RDP, SSH, SMTP and much more