similar to: stopping dictionary attacks (pop3)

I'm seeing strings of failed POP3 login attempts with obvious bogus usernames coming from different IP addresses. Today's originated from 216.31.146.19 (which resolves to neovisionlabs.com). This looks like a botnet attack. I got a similar probe a couple days ago. Is anyone else seeing these? The attack involves trying about 20 different names, about 3-4 seconds apart. Here's a

Hi, I been using dovecot for awhile and its been solid, however I been having some issues with dictionary attacks. I installed fail2ban and for the most part is working fine. However today I got another spammer relaying through my server. Looking at the logs I see the following dictonary attack from 94.242.206.37 Nov 10 03:04:38 pop dovecot: pop3-login: Disconnected: rip=94.242.206.37,

Hi has someone a script which can filter out dictionary attacks from /var/log/maillog and notify about the source-IPs? i know about fail2ban and so on, but i would like to have a mail with the IP address for two reasons and avoid fail2ban at all because it does not match in the way we maintain firewalls * add the IP to a distributed "iptables-block.sh" and distribute it to any

Hi Guys, Running Dovecot 2 on my server. It is regularly getting dictionary auth attacked. What I have noticed is that once connected to a pop3/imap login session, you can send endless incorrect usernames+passwords attempts. This is a problem for me... I use fail2ban to try and stop these script kiddies. The problem is that fail2ban detects the bad auths, firewalls the IP, however,

Hi hoping someone can help me a little with this one. I have 2 mail servers, the incoming mail server runs dovecot and the outgoing mail server runs postfix with sasl. Lately I noticed a lot of spammers are running dictionary attacks on my incoming server and then using that user/password for sasl on the outgoing server. The weird thing is I never see on the logs the guessed

On 1/9/20 2:08 AM, Pete Biggs wrote: >> Has anyone created a fail2ban filter for this type of attack? As of >> right now, I have manually banned a range of IP addresses but would >> like to automate it for the future. >> > As far as I can see fail2ban only deals with hosts and not networks - I > suspect the issue is what is a "network": It may be obvious to

My server is being attached all day and fail2ban is not stopping the attack. I updated stamstamp to match fail2ban requirements. [2010-12-25 18:54:34] NOTICE[15415]: chan_sip.c:21830 handle_request_register: Registration from '"7002" <sip:7002 at x.x.x.x>' failed for '38.108.40.94' - No matching peer found [2010-12-25 18:54:34] NOTICE[15415]: chan_sip.c:21830

Just a note that I did a little work to extend FreePBX distro with some extra Fail2Ban which deals with some drive-by SIP registration attempts. My regex is poor to middling, but the steps detailed here: http://www.coochey.net/?p=61 manage to stop IPs which try to authenticate against Asterisk which FreePBX were not able to stop before. I would welcome any improvements anyone would care to

I am being attacked by an entire subnet where the first two parts of the IP address remain identical but the last two parts vary sufficiently that it is not caught by fail2ban since the attempts do not meet the cut-off of a certain number of attempts within the given time. Has anyone created a fail2ban filter for this type of attack? As of right now, I have manually banned a range of IP addresses

>From my secure log: Sep 19 01:16:44 lin12 dovecot-auth: pam_unix(dovecot:auth): check pass; user unknown Sep 19 01:16:44 lin12 dovecot-auth: pam_unix(dovecot:auth): authentication failure; logname= uid=0 euid=0 tty=dovecot ruser= rhost=::ffff:64.31.19.48 Sep 19 01:16:44 lin12 dovecot-auth: pam_succeed_if(dovecot:auth): error retrieving information about user aaron Sep 19 01:16:45 lin12

Has anyone implemented a script to block IPs which are attacking on POP3 ports using dovecot logs to indicate repetitive failed login attempts? sshblack does this nicely for ssh (port 22) attacks by monitoring the /var/log/secure file. I am considering rewriting this to POP3 port (110), but if it has already been done, I sure don't need the practice. Thanks!

I have experience block DDoS atacks. Contac White me in prived. If you have intereses. El mi?., 8 ene. 2020 8:45 p. m., Keith Christian <keith1christian at gmail.com> escribi?: > On Wed, Jan 8, 2020 at 5:37 PM H <agents at meddatainc.com> wrote: > > > I am being attacked by an entire subnet where the first two parts of the > > IP address remain identical but the

Does dovecot have any dictionary attack defenses yet? In the past I have had to implement defense from outside dovecot, but since dovecot is at the front lines and therefore is the first to know I'm hoping by now there is something we can set. For example, a limit on access failures per minut/hour/day or some such. If not why not?

I was hoping to set up fail2ban to block IP addresses that generate too many Samba password failures, but it needs a syslog message with the IP address of the computer that failed password authentication. Unfortunately, Samba doesn't seem to do this in my environment. Here's a sample error message: smbd[312]: smb_pam_passcheck: PAM: smb_pam_auth failed - Rejecting User brutus ! I

Am 20.07.2017 um 12:28 schrieb mj: > I have concoted something that seems to work. And for the archives, this > is it: > >> failregex = auth: Info: ldap\(.+,<HOST>,.+\): invalid credentials >> \(given password: .+ssword\) >> auth: Info: ldap\(.+,<HOST>,.+\): invalid credentials >> \(given password: 1qaz2wsx\) >> auth:

Well, correct me if I'm wrong, but I would say this conversation you have posted is a bit outdated, now fail2ban can be used with asterisk security log https://wiki.asterisk.org/wiki/display/AST/Asterisk+Security+Event+Logger. On Thu, Aug 17, 2017, 4:53 AM Telium Technical Support <support at telium.ca> wrote: > Keep in mind that the attacks you are seeing in the log are ONLY the

Hi to all, @Olaf Hopp I've this filter enabled for fail2ban, my question is: could my filters overlap or interfere with those suggested by you? this is my filter: Contents of /etc/fail2ban/jail.conf: [postfix] # Ban for 10 minutes if it fails 6 times within 10 minutes enabled = true port = smtp,ssmtp filter = postfix logpath = /var/log/mail.log maxretry = 6 bantime = 600

Hi Robert, On 07/18/2017 11:43 PM, Robert Schetterer wrote: > i guess not, but typical bots arent using ssl, check it > > however fail2ban sometimes is to slow I have configured dovecot with auth_failure_delay = 10 secs I hope that before the 10 sec are over, dovecot will have logged about the failed login attempt, and fail2ban will have blocked the ip by then. MJ

Hi, Thanks for the quick follow-ups! Much appreciated. After posting this, I immediately started working on fail2ban. And between my initial posting and now, fail2ban already blocked 114 IPs. I have fail2ban with maxretry=1 and bantime=1800 However, it seems almost all IPs are different, and I don't think I can keep the above settings permanently. Robert, your iptables suggestions are

Hi all, If I may, one more question on this subject: I would like to create a fail2ban filer, that scans for these lines: > Jul 20 11:10:09 auth: Info: ldap(user1,60.166.35.162,<cDFXHbxUQgA8piOi>): invalid credentials (given password: password) > Jul 20 11:10:19 auth: Info: ldap(user2,61.53.66.4,<V+nyHbxU+wA9NUIE>): invalid credentials (given password: password) (as you can