Mod-security is a (third party) module of Apache (recently Microsoft IIS and NGINX) offering intrusion detection and (some kind of) prevention for web applications, acting as a web application firewall.…
Psad (Port Scan Attack Detector) is an intrusion prevention software, written in Perl by Michael Rash. Psad makes use of iptables and ip6tables log messages to detect, alert, and (optionally)…
Fail2Ban (authentication failure monitor) is an intrusion prevention software, written in Python. Fail2Ban analyzes various services log files (ssh, apache, postfix etc) and if it detects possible attacks (mainly Brute-force…
