fail2ban/config/filter.d/proftpd.conf

# Fail2Ban fitler for the Proftpd FTP daemon
#

[INCLUDES]

before = common.conf

[Definition]

_daemon = proftpd

__suffix_failed_login = (User not authorized for login|No such user found|Incorrect password|Password expired|Account disabled|Invalid shell: '\S+'|User in \S+|Limit (access|configuration) denies login|Not a UserAlias|maximum login length exceeded).?

failregex = ^%(__prefix_line)s%(__hostname)s \(\S+\[<HOST>\]\)[: -]+ USER .*: no such user found from \S+ \[\S+\] to \S+:\S+ *$
            ^%(__prefix_line)s%(__hostname)s \(\S+\[<HOST>\]\)[: -]+ USER .* \(Login failed\): %(__suffix_failed_login)s\s*$
            ^%(__prefix_line)s%(__hostname)s \(\S+\[<HOST>\]\)[: -]+ SECURITY VIOLATION: .* login attempted\. *$
            ^%(__prefix_line)s%(__hostname)s \(\S+\[<HOST>\]\)[: -]+ Maximum login attempts \(\d+\) exceeded *$

ignoreregex = 

# Author: Yaroslav Halchenko
#         Daniel Black - hardening of regex