On 08/10/2014 08:19 AM, Gabriel Marais wrote:
Hi Nanog
I'm curious.
I have been receiving some major ssh brute-force attacks coming from random hosts in the 116.8.0.0 - 116.11.255.255 network. I have sent a complaint to the e-mail addresses obtained from a whois query on one of the IP Addresses.
My e-mail bounced back from both recipients. Once being rejected by filter and the other because the e-mail address doesn't exist. I would have thought that contact details are rather important to be up to date, or not?
Besides just blocking the IP range on my firewall, I was wondering what others would do in this case?
Regards, Gabriel
I no longer try to send notices to network operators that don't publish a working abuse mail address for the netrange assignment or the SWIP. For the best-practices-clueless, I just round-file them when I see attacks above a certain level. Ditto mail attacks, particularly from netranges/servers that don't have working postmaster@ addresses or MX. (I'm considering adding a separate network ACL for SMTP/SUBMISSION in my mail servers, but so far all the verifiable mail abusers have had other bad habits, too.)
From my firewall generator's "kill network" list: 116.10.191.0/24 china ssh abuser 2014 August
That entry went into the ACL six months ago, but it's only recently that I started dating the entries. I now have canaries (tcpwrappers, logwatch) in four systems on widely separate IP netranges. Those systems have a virtually-everything-closed firewall (IPTables, logwatch) and the resulting logs show where some of the most vicious scans are coming from. PLONK!