Fail2ban, IPBanPro, LF Intrusion Detection, AiP Defense, Cyberarms Intrusion Detection and Defense, e.guardo Smart Defender, EvlWatcher, SpyLog, Denyhosts, Anti DDoS Guardian, Syspeace, SSHGuard, win2ban, Hookem-Banem, IPQ BDB are some alternatives to RdpGuard.