The correct way to deal with annoying bots is to block them in "robots.txt". But your comments indicate they're ignoring that directive. Blocking by user-agent will ultimately be a cat and mouse game, but if you want to do it you want the following.
So, you need to enable the apache-badbots jail that reads the Apache access log if you haven't already. Create the file /etc/fail2ban/jail.d/apache-badbots.local with the contents:
[apache-badbots]
enabled = true
The main portion of the apache-badbots jail is defined in /etc/fail2ban/jail.conf so all you have to do is enable it.
Next, modify the apache-badbots filter to include your bots. Edit /etc/fail2ban/filter.d/apache-badbots.conf. In it there is a particular line for custom bots:
badbotscustom = EmailCollector|WebEMailExtrac|TrackBack/1\.02|sogou music spider
The bots are specified using a regular expression. Either replace those or tack yours on the end separated with |s.
badbotscustom = EmailCollector|WebEMailExtrac|TrackBack/1\.02|sogou music spider|BLEXBot|ltx71|DotBot|Barkrowler
# OR
badbotscustom = BLEXBot|ltx71|DotBot|Barkrowler
Next, you'll want to modify the failregex line so that the regular expression matches any part of the user agent, not just the whole thing. Change the line:
failregex = ^<HOST> -.*"(GET|POST).*HTTP.*"(?:%(badbots)s|%(badbotscustom)s)"$
to (note the two additional .*):
failregex = ^<HOST> -.*"(GET|POST).*HTTP.*".*(?:%(badbots)s|%(badbotscustom)s).*"$
Finally, reload the fail2ban configurations.
sudo fail2ban-client reload
This information may be helpful for reference.
Looking at /etc/fail2ban/filter.d/apache-badbots.conf on an update to date Ubuntu 16.04 server I have, it looks outdated. In particular there's this comment:
# DEV Notes:
# List of bad bots fetched from http://www.user-agents.org
# Generated on Thu Nov 7 14:23:35 PST 2013 by files/gen_badbots.
I generated a new one from the fail2ban git repository, but it still didn't include those bots (maybe the source is outdated or incomplete). If you're curious, you can generate a new one with following.
git clone https://github.com/fail2ban/fail2ban
cd fail2ban/
./files/gen_badbots
The new file will be available at config/filter.d/apache-badbots.conf (here on Github). If you want to use it replace /etc/fail2ban/filter.d/apache-badbots.conf with it.
For reference, this is the definition of apache-badbots from /etc/fail2ban/jail.conf.
[apache-badbots]
# Ban hosts which agent identifies spammer robots crawling the web
# for email addresses. The mail outputs are buffered.
port = http,https
logpath = %(apache_access_log)s
bantime = 172800
maxretry = 1
The %(apache_access_log)s variable comes from /etc/fail2ban/paths-debian.conf and is defined as /var/log/apache2/*access.log.
For reference, here is the apache-badbots.conf that I generated (without modifications).
# Fail2Ban configuration file
#
# Regexp to catch known spambots and software alike. Please verify
# that it is your intent to block IPs which were driven by
# above mentioned bots.
[Definition]
badbotscustom = EmailCollector|WebEMailExtrac|TrackBack/1.02|sogou music spider
badbots = Atomic_Email_Hunter/4.0|atSpider/1.0|autoemailspider|bwh3_user_agent|China Local Browse 2.6|ContactBot/0.2|ContentSmartz|DataCha0s/2.0|DBrowse 1.4b|DBrowse 1.4d|Demo Bot DOT 16b|Demo Bot Z 16b|DSurf15a 01|DSurf15a 71|DSurf15a 81|DSurf15a VA|EBrowse 1.4b|Educate Search VxB|EmailSiphon|EmailSpider|EmailWolf 1.00|ESurf15a 15|ExtractorPro|Franklin Locator 1.8|FSurf15a 01|Full Web Bot 0416B|Full Web Bot 0516B|Full Web Bot 2816B|8484 Boston Project v 1.0|Atomic_Email_Hunter/4.0|atSpider/1.0|autoemailspider|bwh3_user_agent|China Local Browse 2.6|ContactBot/0.2|ContentSmartz|DataCha0s/2.0|DBrowse 1.4b|DBrowse 1.4d|Demo Bot DOT 16b|Demo Bot Z 16b|DSurf15a 01|DSurf15a 71|DSurf15a 81|DSurf15a VA|EBrowse 1.4b|Educate Search VxB|EmailSiphon|EmailSpider|EmailWolf 1.00|ESurf15a 15|ExtractorPro|Franklin Locator 1.8|FSurf15a 01|Full Web Bot 0416B|Full Web Bot 0516B|Full Web Bot 2816B|8484 Boston Project v 1.0|Atomic_Email_Hunter/4.0|atSpider/1.0|autoemailspider|bwh3_user_agent|China Local Browse 2.6|ContactBot/0.2|ContentSmartz|DataCha0s/2.0|DBrowse 1.4b|DBrowse 1.4d|Demo Bot DOT 16b|Demo Bot Z 16b|DSurf15a 01|DSurf15a 71|DSurf15a 81|DSurf15a VA|EBrowse 1.4b|Educate Search VxB|EmailSiphon|EmailSpider|EmailWolf 1.00|ESurf15a 15|ExtractorPro|Franklin Locator 1.8|FSurf15a 01|Full Web Bot 0416B|Full Web Bot 0516B|Full Web Bot 2816B|8484 Boston Project v 1.0|Atomic_Email_Hunter/4.0|atSpider/1.0|autoemailspider|bwh3_user_agent|China Local Browse 2.6|ContactBot/0.2|ContentSmartz|DataCha0s/2.0|DBrowse 1.4b|DBrowse 1.4d|Demo Bot DOT 16b|Demo Bot Z 16b|DSurf15a 01|DSurf15a 71|DSurf15a 81|DSurf15a VA|EBrowse 1.4b|Educate Search VxB|EmailSiphon|EmailSpider|EmailWolf 1.00|ESurf15a 15|ExtractorPro|Franklin Locator 1.8|FSurf15a 01|Full Web Bot 0416B|Full Web Bot 0516B|Full Web Bot 2816B|8484 Boston Project v 1.0|Atomic_Email_Hunter/4.0|atSpider/1.0|autoemailspider|bwh3_user_agent|China Local Browse 2.6|ContactBot/0.2|ContentSmartz|DataCha0s/2.0|DBrowse 1.4b|DBrowse 1.4d|Demo Bot DOT 16b|Demo Bot Z 16b|DSurf15a 01|DSurf15a 71|DSurf15a 81|DSurf15a VA|EBrowse 1.4b|Educate Search VxB|EmailSiphon|EmailSpider|EmailWolf 1.00|ESurf15a 15|ExtractorPro|Franklin Locator 1.8|FSurf15a 01|Full Web Bot 0416B|Full Web Bot 0516B|Full Web Bot 2816B
failregex = ^<HOST> -."(GET|POST).HTTP.*"(?:%(badbots)s|%(badbotscustom)s)"$
ignoreregex =
DEV Notes:
List of bad bots fetched from http://www.user-agents.org
Generated on Sat Feb 9 12:59:57 EST 2019 by ./files/gen_badbots.
Author: Yaroslav Halchenko
