I host my blog in cloud server, and I set up ssh to manage my Ubuntu Linux 16.04 LTS server. However, I noticed lots of break in and brute-force attacks on my ssh server? How can I stop hacking attempts into my system?
You need to use DenyHosts which is a log-based intrusion prevention security tool for SSH servers written in Python. It is designed to prevent brute-force attacks on SSH servers by monitoring invalid login attempts in the authentication log and blocking the originating IP addresses using /etc/hosts.deny and iptables on Linux server.