Порядок поиска разрешения имен в Unix / Linux
Я получаю разные SSH-атаки с одних и тех же IP-адресов, и их забанят. Но они используют другой порт, и все, что им нужно сделать, это изменить порт, чтобы обойти запрет.
Dec 28 23:16:57 Nixie sshd[30706]: Failed password for root from 40.127.178.38 port 3424 ssh2
Dec 28 23:16:54 Nixie sshd[30704]: Failed password for root from 40.127.178.38 port 1112 ssh2
Dec 28 23:16:51 Nixie sshd[30702]: Failed password for root from 40.127.178.38 port 1116 ssh2
Dec 28 23:16:47 Nixie sshd[30700]: Failed password for root from 40.127.178.38 port 1115 ssh2
Dec 28 23:16:43 Nixie sshd[30698]: Failed password for root from 40.127.178.38 port 1114 ssh2
Dec 28 23:16:40 Nixie sshd[30696]: Failed password for root from 40.127.178.38 port 1113 ssh2
Dec 28 23:16:37 Nixie sshd[30694]: Failed password for root from 40.127.178.38 port 3424 ssh2
Dec 28 23:16:33 Nixie sshd[30692]: Failed password for root from 40.127.178.38 port 1112 ssh2
Вот мой файл jail.local:
# Fail2Ban configuration file.
#
# This file was composed for Debian systems from the original one
# provided now under /usr/share/doc/fail2ban/examples/jail.conf
# for additional examples.
#
# Comments: use '#' for comment lines and ';' for inline comments
#
# To avoid merges during upgrades DO NOT MODIFY THIS FILE
# and rather provide your changes in /etc/fail2ban/jail.local
#
# The DEFAULT allows a global definition of the options. They can be overridden
# in each jail afterwards.
[DEFAULT]
# "ignoreip" can be an IP address, a CIDR mask or a DNS host. Fail2ban will not
# ban a host which matches an address in this list. Several addresses can be
# defined using space separator.
ignoreip = 127.0.0.1/8
# "bantime" is the number of seconds that a host is banned.
bantime = 3600
# A host is banned if it has generated "maxretry" during the last "findtime"
# seconds.
findtime = 600
maxretry = 3
# "backend" specifies the backend used to get files modification.
# Available options are "pyinotify", "gamin", "polling" and "auto".
# This option can be overridden in each jail as well.
#
# pyinotify: requires pyinotify (a file alteration monitor) to be installed.
# If pyinotify is not installed, Fail2ban will use auto.
# gamin: requires Gamin (a file alteration monitor) to be installed.
# If Gamin is not installed, Fail2ban will use auto.
# polling: uses a polling algorithm which does not require external libraries.
# auto: will try to use the following backends, in order:
# pyinotify, gamin, polling.
backend = auto
# "usedns" specifies if jails should trust hostnames in logs,
# warn when reverse DNS lookups are performed, or ignore all hostnames in logs
#
# yes: if a hostname is encountered, a reverse DNS lookup will be performed.
# warn: if a hostname is encountered, a reverse DNS lookup will be performed,
# but it will be logged as a warning.
# no: if a hostname is encountered, will not be used for banning,
# but it will be logged as info.
usedns = warn
#
# Destination email address used solely for the interpolations in
# jail.{conf,local} configuration files.
destemail = root@localhost
#
# Name of the sender for mta actions
sendername = Fail2Ban
#
# ACTIONS
#
# Default banning action (e.g. iptables, iptables-new,
# iptables-multiport, shorewall, etc) It is used to define
# action_* variables. Can be overridden globally or per
# section within jail.local file
banaction = iptables-allports
# email action. Since 0.8.1 upstream fail2ban uses sendmail
# MTA for the mailing. Change mta configuration parameter to mail
# if you want to revert to conventional 'mail'.
mta = sendmail
# Default protocol
protocol = tcp
# Specify chain where jumps would need to be added in iptables-* actions
chain = INPUT
#
# Action shortcuts. To be used to define action parameter
# The simplest action to take: ban only
action_ = %(banaction)s[name=%(__name__)s, port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
# ban & send an e-mail with whois report to the destemail.
action_mw = %(banaction)s[name=%(__name__)s, port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
%(mta)s-whois[name=%(__name__)s, dest="%(destemail)s", protocol="%(protocol)s", chain="%(chain)s", sendername="%(sendername)s"]
# ban & send an e-mail with whois report and relevant log lines
# to the destemail.
action_mwl = %(banaction)s[name=%(__name__)s, port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
%(mta)s-whois-lines[name=%(__name__)s, dest="%(destemail)s", logpath=%(logpath)s, chain="%(chain)s", sendername="%(sendername)s"]
# Choose default action. To change, just override value of 'action' with the
# interpolation to the chosen action shortcut (e.g. action_mw, action_mwl, etc) in jail.local
# globally (section [DEFAULT]) or per specific section
action = %(action_)s
#
# JAILS
#
# Next jails corresponds to the standard configuration in Fail2ban 0.6 which
# was shipped in Debian. Enable any defined here jail by including
#
# [SECTION_NAME]
# enabled = true
#
# in /etc/fail2ban/jail.local.
#
# Optionally you may override any other parameter (e.g. banaction,
# action, port, logpath, etc) in that section within jail.local
[ssh]
enabled = true
port = ssh
filter = sshd
logpath = /var/log/auth.log
maxretry = 3
[dropbear]
enabled = false
port = ssh
filter = dropbear
logpath = /var/log/auth.log
maxretry = 6
# Generic filter for pam. Has to be used with action which bans all ports
# such as iptables-allports, shorewall
[pam-generic]
enabled = false
# pam-generic filter can be customized to monitor specific subset of 'tty's
filter = pam-generic
# port actually must be irrelevant but lets leave it all for some possible uses
port = all
banaction = iptables-allports
port = anyport
logpath = /var/log/auth.log
maxretry = 6
[xinetd-fail]
enabled = false
filter = xinetd-fail
port = all
banaction = iptables-multiport-log
logpath = /var/log/daemon.log
maxretry = 2
[ssh-ddos]
enabled = false
port = ssh
filter = sshd-ddos
logpath = /var/log/auth.log
maxretry = 6
# Here we use blackhole routes for not requiring any additional kernel support
# to store large volumes of banned IPs
[ssh-route]
enabled = false
filter = sshd
action = route
logpath = /var/log/sshd.log
maxretry = 6
# Here we use a combination of Netfilter/Iptables and IPsets
# for storing large volumes of banned IPs
#
# IPset comes in two versions. See ipset -V for which one to use
# requires the ipset package and kernel support.
[ssh-iptables-ipset4]
enabled = false
port = ssh
filter = sshd
banaction = iptables-ipset-proto4
logpath = /var/log/sshd.log
maxretry = 6
[ssh-iptables-ipset6]
enabled = false
port = ssh
filter = sshd
banaction = iptables-ipset-proto6
logpath = /var/log/sshd.log
maxretry = 6
#
# HTTP servers
#
[apache]
enabled = false
port = http,https
filter = apache-auth
logpath = /var/log/apache*/*error.log
maxretry = 6
# default action is now multiport, so apache-multiport jail was left
# for compatibility with previous (<0.7.6-2) releases
[apache-multiport]
enabled = false
port = http,https
filter = apache-auth
logpath = /var/log/apache*/*error.log
maxretry = 6
[apache-noscript]
enabled = false
port = http,https
filter = apache-noscript
logpath = /var/log/apache*/*error.log
maxretry = 6
[apache-overflows]
enabled = false
port = http,https
filter = apache-overflows
logpath = /var/log/apache*/*error.log
maxretry = 2
# Ban attackers that try to use PHP's URL-fopen() functionality
# through GET/POST variables. - Experimental, with more than a year
# of usage in production environments.
[php-url-fopen]
enabled = false
port = http,https
filter = php-url-fopen
logpath = /var/www/*/logs/access_log
# A simple PHP-fastcgi jail which works with lighttpd.
# If you run a lighttpd server, then you probably will
# find these kinds of messages in your error_log:
# ALERT – tried to register forbidden variable ‘GLOBALS’
# through GET variables (attacker '1.2.3.4', file '/var/www/default/htdocs/index.php')
[lighttpd-fastcgi]
enabled = false
port = http,https
filter = lighttpd-fastcgi
logpath = /var/log/lighttpd/error.log
# Same as above for mod_auth
# It catches wrong authentifications
[lighttpd-auth]
enabled = false
port = http,https
filter = suhosin
logpath = /var/log/lighttpd/error.log
[nginx-http-auth]
enabled = true
filter = nginx-http-auth
port = http,https
logpath = /var/log/nginx/error.log
# Monitor roundcube server
[roundcube-auth]
enabled = false
filter = roundcube-auth
port = http,https
logpath = /var/log/roundcube/userlogins
[sogo-auth]
enabled = false
filter = sogo-auth
port = http, https
# without proxy this would be:
# port = 20000
logpath = /var/log/sogo/sogo.log
#
# FTP servers
#
[vsftpd]
enabled = false
port = ftp,ftp-data,ftps,ftps-data
filter = vsftpd
logpath = /var/log/vsftpd.log
# or overwrite it in jails.local to be
# logpath = /var/log/auth.log
# if you want to rely on PAM failed login attempts
# vsftpd's failregex should match both of those formats
maxretry = 6
[proftpd]
enabled = false
port = ftp,ftp-data,ftps,ftps-data
filter = proftpd
logpath = /var/log/proftpd/proftpd.log
maxretry = 6
[pure-ftpd]
enabled = false
port = ftp,ftp-data,ftps,ftps-data
filter = pure-ftpd
logpath = /var/log/syslog
maxretry = 6
[wuftpd]
enabled = false
port = ftp,ftp-data,ftps,ftps-data
filter = wuftpd
logpath = /var/log/syslog
maxretry = 6
#
# Mail servers
#
[postfix]
enabled = false
port = smtp,ssmtp,submission
filter = postfix
logpath = /var/log/mail.log
[couriersmtp]
enabled = false
port = smtp,ssmtp,submission
filter = couriersmtp
logpath = /var/log/mail.log
#
# Mail servers authenticators: might be used for smtp,ftp,imap servers, so
# all relevant ports get banned
#
[courierauth]
enabled = false
port = smtp,ssmtp,submission,imap2,imap3,imaps,pop3,pop3s
filter = courierlogin
logpath = /var/log/mail.log
[sasl]
enabled = false
port = smtp,ssmtp,submission,imap2,imap3,imaps,pop3,pop3s
filter = postfix-sasl
# You might consider monitoring /var/log/mail.warn instead if you are
# running postfix since it would provide the same log lines at the
# "warn" level but overall at the smaller filesize.
logpath = /var/log/mail.log
[dovecot]
enabled = false
port = smtp,ssmtp,submission,imap2,imap3,imaps,pop3,pop3s
filter = dovecot
logpath = /var/log/mail.log
# To log wrong MySQL access attempts add to /etc/my.cnf:
# log-error=/var/log/mysqld.log
# log-warning = 2
[mysqld-auth]
enabled = false
filter = mysqld-auth
port = 3306
logpath = /var/log/mysqld.log
# DNS Servers
# These jails block attacks against named (bind9). By default, logging is off
# with bind9 installation. You will need something like this:
#
# logging {
# channel security_file {
# file "/var/log/named/security.log" versions 3 size 30m;
# severity dynamic;
# print-time yes;
# };
# category security {
# security_file;
# };
# };
#
# in your named.conf to provide proper logging
# !!! WARNING !!!
# Since UDP is connection-less protocol, spoofing of IP and imitation
# of illegal actions is way too simple. Thus enabling of this filter
# might provide an easy way for implementing a DoS against a chosen
# victim. See
# http://nion.modprobe.de/blog/archives/690-fail2ban-+-dns-fail.html
# Please DO NOT USE this jail unless you know what you are doing.
#[named-refused-udp]
#
#enabled = false
#port = domain,953
#protocol = udp
#filter = named-refused
#logpath = /var/log/named/security.log
[named-refused-tcp]
enabled = false
port = domain,953
protocol = tcp
filter = named-refused
logpath = /var/log/named/security.log
# Multiple jails, 1 per protocol, are necessary ATM:
# see https://github.com/fail2ban/fail2ban/issues/37
[asterisk-tcp]
enabled = false
filter = asterisk
port = 5060,5061
protocol = tcp
logpath = /var/log/asterisk/messages
[asterisk-udp]
enabled = false
filter = asterisk
port = 5060,5061
protocol = udp
logpath = /var/log/asterisk/messages
# Jail for more extended banning of persistent abusers
# !!! WARNING !!!
# Make sure that your loglevel specified in fail2ban.conf/.local
# is not at DEBUG level -- which might then cause fail2ban to fall into
# an infinite loop constantly feeding itself with non-informative lines
[recidive]
enabled = false
filter = recidive
logpath = /var/log/fail2ban.log
action = iptables-allports[name=recidive]
sendmail-whois-lines[name=recidive, logpath=/var/log/fail2ban.log]
bantime = 604800 ; 1 week
findtime = 86400 ; 1 day
maxretry = 5
Почему не блокируются IP-адреса?
Вот мой filter.d / sshd.conf
# Fail2Ban filter for openssh
#
[INCLUDES]
# Read common prefixes. If any customizations available -- read them from
# common.local
before = common.conf
[Definition]
_daemon = sshd
failregex = ^%(__prefix_line)s(?:error: PAM: )?[aA]uthentication (?:failure|error) for .* from <HOST>( via \S+)?\s*$
^%(__prefix_line)s(?:error: PAM: )?User not known to the underlying authentication module for .* from <HOST>\s*$
^%(__prefix_line)sFailed \S+ for .*? from <HOST>(?: port \d*)?(?: ssh\d*)?(: (ruser .*|(\S+ ID \S+ \(serial \d+\) CA )?\S+ %(__md5hex)s(, client user ".*", client host ".*")?))?\s*$
^%(__prefix_line)sROOT LOGIN REFUSED.* FROM <HOST>\s*$
^%(__prefix_line)s[iI](?:llegal|nvalid) user .* from <HOST>\s*$
^%(__prefix_line)sUser .+ from <HOST> not allowed because not listed in AllowUsers\s*$
^%(__prefix_line)sUser .+ from <HOST> not allowed because listed in DenyUsers\s*$
^%(__prefix_line)sUser .+ from <HOST> not allowed because not in any group\s*$
^%(__prefix_line)srefused connect from \S+ \(<HOST>\)\s*$
^%(__prefix_line)sUser .+ from <HOST> not allowed because a group is listed in DenyGroups\s*$
^%(__prefix_line)sUser .+ from <HOST> not allowed because none of user's groups are listed in AllowGroups\s*$
ignoreregex =
# DEV Notes:
#
# "Failed \S+ for .*? from <HOST>..." failregex uses non-greedy catch-all because
# it is coming before use of <HOST> which is not hard-anchored at the end as well,
# and later catch-all's could contain user-provided input, which need to be greedily
# matched away first.
#
# Author: Cyril Jaquier, Yaroslav Halchenko, Petr Voralek, Daniel Black
Вывод iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
DROP all -- 43.229.53.66 anywhere
DROP all -- 58.218.211.38 anywhere
DROP all -- 124.173.68.198 anywhere
DROP all -- 183.56.173.20 anywhere
Chain FORWARD (policy ACCEPT)
target prot opt source destination
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
2
задан Raymond Luna
29 December 2015 в 18:38
Ссылка
1 ответ
Вполне возможно, что sshd.filter не соответствует вашим строкам. Установленный мной фильтр не соответствует этим строкам. Существует утилита fail2ban-regex , которую можно использовать для проверки вашего регулярного выражения. Многострочная строка в регулярном выражении содержит несколько регулярных выражений, по одному на строку.
Регулярное выражение, подобное приведенному ниже, может быть лучше. Я думаю, что существующее регулярное выражение не находит достаточно данных.
^%(__prefix_line)sFailed \S+ for .*? from <HOST>(?: port \d*)?(?: ssh\d*)?
При тестировании вам может потребоваться определить такие вещи, как __ prefix_line в тестовом сценарии. Затем попробуйте сопоставить несколько записей, извлеченных из вашего файла журнала.
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