Fighting dictionary attacks with Sshutout and Fail2ban
Closing the Book
© Andriy Solovyov, Fotolia
Services that require a username and password for login are potential targets for dictionary attacks. Sshutout and Fail2ban introduce time penalties for invalid attempts.
Sshutout [1] is a daemon written in C that checks a logfile for invalid SSH logins at frequent intervals. If Sshutout discovers a pattern of failed login attempts by a client, it blocks the client according to iptables rules. After a configurable delay, the penalty is automatically revoked.
Activating the Ban
All it takes to install the 32KB tarball is the usual make; make install.
The daemon is located in /usr/local/sbin after the install, and its configuration file is /etc/sshutout.conf.
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