Security Incidents mailing list archives
Re: Weird SSH attack last night and this morning (still ongoing)
From: Robert Taylor <rjamestaylor () gmail com>
Date: Wed, 7 May 2008 13:23:33 -0500
Good points.I plead exhaustion for missing the key differentiator of this attack : one attempt at root (likely the null password attack, as a guess). Reason for my tiredness? I'm a third shift admin.
Thank you for the clarification. On May 7, 2008, at 1:15 PM, Erin Carroll wrote:
Robert, I agree that this kind of traffic/attack is extremely common. The onlynotable thing about this one is the very slow attack interval perceived by the individual targets. Instead of hammering away at a single target it looks like a botnet which is cycling through a large list of targets to spread the attack around and more likely sneak in under the radar. That way the botnet can leverage its size to run thousands of attacks simultaneously but limit the risk of alerting the individual targets since each destination is hit with attempts in a small trickle. This method of attack is not socommon.It's easy to see or be alerted on the defense side of hundreds or thousands of failed attempts but a couple an hour from all different IP's? Fairly easy to imagine this slipping past most automated defense or threshold- based protections alerts for organizations. Fail2ban, denyhosts, and other ways of automating response need the threshold to be reached to blackhole/ null the attacker source. This attack pattern seems explicitly designed to bypassthose types of controls which is what makes it interesting. -- Erin Carroll Moderator, SecurityFocus pen-test mailing list amoeba () amoebazone com "Do Not Taunt Happy-Fun Ball" -----Original Message----- From: Robert Taylor [mailto:rjamestaylor () gmail com] Sent: Wednesday, May 07, 2008 10:04 AM To: Gary Baribault Cc: incidents () securityfocus comSubject: Re: Weird SSH attack last night and this morning (still ongoing)It's extremely common to have these scans. http://robotterror.com/site/wiki/mitigating_brute_force_password_attacks_wit h_pam_abl That's a link to my blog. I'm a Linux System Admin at a major hosting company; this is something I see nightly. Usually, though, I see hits on the order of thousands per hour before I get worried. On May 7, 2008, at 7:27 AM, Gary Baribault wrote:I don't know what is going on last night and this morning ... I have three Linux servers facing the Internet, two on cable modems and another on a static IP/commercial connection and this last one is a gateway to a Web/FTP/SMTP/Pop3/NTP Linux based system. I have DenyHosts installed on all three and have blocked about 75 attempts .. from known compromised adresses .. The log shows (obviously) that there where even more attempts from adresses that are unknown to DenyHosts but there was only one login attemps per adress and it was with the Root account .. which is obviously blocked in my sshd config .. Of the three machines, one of them only had about 10 attempts, but the other two had about 200 attempts .. all of them with only 1 try with the user Root .. Is any one else seing this? or am I being targeted? This is still going on now .. and it started arround 10:00 last night GMT+4 -- Gary Baribault Courriel: gary () baribault net GPG Key: 0x4346F013 GPG Fingerprint: BCE8 2E6B EB39 9B23 6904 1DF4 C4E6 2CF7 4346 F013
Current thread:
- Weird SSH attack last night and this morning (still ongoing) Gary Baribault (May 07)
- Re: Weird SSH attack last night and this morning (still ongoing) Robert Taylor (May 07)
- RE: Weird SSH attack last night and this morning (still ongoing) Erin Carroll (May 07)
- Re: Weird SSH attack last night and this morning (still ongoing) Robert Taylor (May 07)
- RE: Weird SSH attack last night and this morning (still ongoing) Erin Carroll (May 07)
- RE: Weird SSH attack last night and this morning (still ongoing) Erin Carroll (May 07)
- Re: Weird SSH attack last night and this morning (still ongoing) Robert Taylor (May 07)
- Re: Weird SSH attack last night and this morning (still ongoing) Blaine Fleming (May 07)
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- Re: Weird SSH attack last night and this morning (still ongoing) Gary Baribault (May 07)
- Re: Weird SSH attack last night and this morning (still ongoing) Bartholomew Mallio (May 07)
- Re: Weird SSH attack last night and this morning (still ongoing) Gary Baribault (May 07)
- RE: Weird SSH attack last night and this morning (still ongoing) Erin Carroll (May 07)
- Message not available
- Re: Weird SSH attack last night and this morning (still ongoing) Gary Baribault (May 07)
- Message not available
- Re: Weird SSH attack last night and this morning (still ongoing) Valdis . Kletnieks (May 07)
- Re: Weird SSH attack last night and this morning (still ongoing) Gary Baribault (May 07)