custom fail2ban filters

fail2Ban is a very handy tool to prevent a lot of unwanted traffic from consuming bandwidth on your servers. It’s a very small and relatively simple IDS Type Tool that comes with some predefined Filters to automatically lockout potentially dangerous or bandwidth-consuming type attacks.

Creating a Custom Filter

/etc/fail2ban/filter.d/custom.conf
[Definition]
 
badagents = 360Spider|ZmEu|Auto Spider 1.0|zgrab/[0-9]*\.[0-9a-zA-Z]*|Wget\(.*\)|MauiBot.*
 
failregex = ^.+?:\d+ <HOST> -.*"(GET|POST|HEAD).*HTTP.*(?:%(badagents)s)"$
 
ignoreregex =

Testing

fail2ban-regex /path-to-samples/sample.log /etc/fail2ban/filter.d/custom.conf

Jail example

[apache-custom]
enabled  = true
logpath  = /var/log/apache*/access.log
		   /var/log/apache*/ssl_access.log
action   = iptables-ipset-proto4[name=Custom, port=1010, protocol=tcp]
findtime = 86400
bantime  = -1
maxretry = 1

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