similar to: No tcp wrappers, other ideas to help stop brute force attacks?

just wanted to get some feedback from the community. Over the last few days I have noticed my web server and email box have attempted to ssh'd to using weird names like admin,appuser,nobody,etc.... None of these are valid users. I know that I can block sshd all together with iptables but that will not work for us. I did a little research on google and found programs like sshguard and

Hello, What is the best way to protect multiuser systems from brute force attacks? I am setting up a relatively loose DenyHosts policy, but I like the idea of locking an account for a time if too many attempts are made, but to balance this with keeping the user from making a helpdesk call. What are some policies/techniques that have worked for this list with minimal hassle? Thanks! -Eugene

We have several web applications deployed under Apache that require a user id / password authentication. Some of these use htdigest and others use the application itself. Recently we have experienced several brute force attacks against some of these services which have been dealt with for the nonce by changes to iptables. However, I am not convinced that these changes are the answer. Therefore

On 25.04.24 17:15, openssh-unix-dev-request at mindrot.org digested: > Subject: how to block brute force attacks on reverse tunnels? > From: Steve Newcomb <srn at coolheads.com> > Date: 25.04.24, 17:14 > > For many years I've been running ssh reverse tunnels on portable Linux, > OpenWRT, Android etc. hosts so they can be accessed from a server whose > IP is stable

Hello list. I'm trying to find a way to block any ip that tries to login more than three times with the wrong password and try to log in three different extensions. For I have suffered some brute force attacks on my asterisk in the morning period. The idea would be: Any ip with three attempts without success to log into an extension is blocked. Is there any way to accomplish this directly

Message-ID: <479F2A63.2070408 at centos.org> On: Tue, 29 Jan 2008 07:30:11 -0600, Johnny Hughes <johnny at centos.org> Subject Was: [CentOS] Unknown rootkit causes compromised servers > > SOME of the script kiddies check higher ports for SSH *_BUT_* I only see > 4% of the brute force attempts to login on ports other than 22. > > I would say that dropping brute force

Hello, I've installed denyhosts on centos 5.3 trying to block automated attacks on ssh. It appears to be working in that entries are being added to /etc/hosts.deny yet the daily emails sent from denyhosts show only one ip being added perday when the total is many more than that. My config is below, i've gone over it and am not seeing what i missed. Suggestions welcome. I was also

I was wondering if anyone had implemented rules like this in shorewall: http://blog.andrew.net.au/tech I see tons of brute force attempts on the machines I administer, and I like the idea of limiting them without the need for extra daemons scanning for attacks. Thanks, Dale -- Dale E. Martin - dale@the-martins.org http://the-martins.org/~dmartin

Hi, to prevent scripted dictionary attacks to sshd I applied those iptables rules: -A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -m recent --update --seconds 60 --hitcount 4 --name SSH --rsource -j DROP -A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -m recent --set --name SSH --rsource And this is part of logwatch: sshd: Authentication Failures: unknown

Over the weekend one of our servers at a remote location was hammered by an IP originating in mainland China. This attack was only noteworthy in that it attempted to connect to our pop3 service. We have long had an IP throttle on ssh connections to discourage this sort of thing. But I had not considered the possibility that other services were equally at risk. Researching this on the web does

For many years I've been running ssh reverse tunnels on portable Linux, OpenWRT, Android etc. hosts so they can be accessed from a server whose IP is stable (I call such a server a "nexus host"). Increasingly there's a problem with brute force attacks on the nexus host's tunnel ports. The attack is forwarded to the portable tunneling host, where it fails, but it chews up

Hi, I just set up a web server... and my bandwidth is being eaten by some chinese folks trying to brute-force-ssh their way into the machine. Is there a simple way to banish either single IP addresses or, maybe even better, whole IP classes ? I know it's feasible with iptables, but is there something more easily configurable ? Cheers, Niki

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

Hi We've just noticed attempts (close to 200000 attempts, sequential peer numbers) at guessing peers on 2 of out servers and thought I'd share the originating IPs with the list in case anyone wants to firewall them as we have done 109.170.106.59 112.142.55.18 124.157.161.67 Ish -- Ishfaq Malik Software Developer PackNet Ltd Office: 0161 660 3062 -------------- next part

Hello, yesterday one of the extensions on my asterisk server got compromised by brute-force attack. The attacker used it to try pull an identity theft scam playing a recording from a bank "your account has been blocked due to unusual activity, please call this number..." Attacker managed to make lots of calls for around 8 hours before I detected it and changed the password for that

Hi List, optimizing the configuration on one of our servers (which was hit by a brute force attack on dovecot) showed an odd behavior. The short story: On one of our servers an attacker did a brute force attack on dovecot (pop3). Since the attacker closed and reopened the connection after every user/password combination the logs showed many lines like this: dovecot: pop3-login: Aborted

Hi, i have one centos 4.3 box, exposed to the internet. since several weeks ago, i found numerous attemps to connect through SSH, but failed. they tried with many username, including root. it's comes from different IP. some of them are foreign website. How do i make my centos become smarter in handling this kind of attacks. eventhough i've disable all the user accounts, left only the

Hi Everyone, Before I begin, I'd just like to mention: I love dovecot. Thank you :) Anyway, today I had 8000 login attempts to my dovecot server in an hour before blocking the IP with my firewall. After googling, I didn't see very much discussion on the topic. There was some mention of blocksshd which was supposed to support dovecot in the next release (but doesn't appear to) and

Hi List, optimizing the configuration on one of our servers (which was hit by a brute force attack on dovecot) showed an odd behavior. Dovecot Version 1.0.7 (CentOS 5.2) The short story: On one of our servers an attacker did a brute force attack on dovecot (pop3). Since the attacker closed and reopened the connection after every user/password combination the logs showed many lines like

Hi, I am kind of restricted to using packaged versions of software due to company policy, and we have f12 on our mail server with dovecot-1.2.15-2.fc12.i686 package. we have recently had some brute force attacks on the pop3 and imapd and this results in many processes being used for login attempts. Our dovecot is hosted on a Virtual Private Server which restricts access to IPTABLEs and also