[ale] [OT] Chinese brute-force network?

[JD]

Should any approved user ever connect from China?
If not, block all ssh from that country, period.

Why risk random success?

On 05/31/2014 02:00 PM, Dustin Strickland wrote:
>> zgrep -c 116.10.191 /var/log/auth*
>> /var/log/auth.log:30666
>> /var/log/auth.log.1.gz:54753
>> /var/log/auth.log.2.gz:36340
>> /var/log/auth.log.3.gz:58485
>> /var/log/auth.log.4.gz:36654
> 
> Jesus, that's quite a few attempts... Anyway, thanks for the tips,
> everybody. I was considering running Fail2ban on my web-facing machine,
> but I haven't gotten around to installing and configuring it because
> I don't have anything of much importance on it. It's got
> reasonable security, anyway -- I know what people think about
> password-based authentication, but my shortest password on that machine
> is around 30-35 characters so I'm not too worried about anybody
> accidentally finding it without some warning. Maybe I should set up a
> honeypot - I kind of like watching the trends in who's trying to get in
> to the machine.
> 
> My main concern was that the attacks weren't coming from a single
> source, but from a range of IPs. And I can't find anything about the
> ISP that owns these adresses, though the name Chinanet-GX appears a few
> times. Is this common? And what exactly is this? Virus-infested PCs, or
> something a little more sinister?
> 
> I did a dirty nmap of the range. If anyone cares to look at it, I'll
> post it.
> 
> On Fri, 30 May 2014 14:24:24 -0400
> Bob Toxen <transam at verysecurelinux.com> wrote:
> 
>> Dustin,
>>
>> Seems to be a serious problem dating back to 04/27/2014:
>>
>> zgrep -c 116.10.191 /var/log/auth*
>> /var/log/auth.log:30666
>> /var/log/auth.log.1.gz:54753
>> /var/log/auth.log.2.gz:36340
>> /var/log/auth.log.3.gz:58485
>> /var/log/auth.log.4.gz:36654
>>
>> We blocked it with Fail2Ban.  (We also have other protections.)  I've
>> now added something similar to the following IP Tables rules:
>>
>> /usr/sbin/iptables -I INPUT   1 -s 116.10.191.0/24 -j DROP
>> #hacker-extreme-brute-Chinese /usr/sbin/iptables -I FORWARD 1 -s
>> 116.10.191.0/24 -j DROP
>> #hacker-extreme-brute-Chinese /usr/sbin/iptables -I INPUT   2 -s
>> 116.10.191.0/24 -j LOG
>> #hacker-extreme-brute-Chinese /usr/sbin/iptables -I FORWARD 2 -s
>> 116.10.191.0/24 -j LOG  #hacker-extreme-brute-Chinese
>>
>> Bob
>>
>> On Thu, May 29, 2014 at 04:03:17PM -0400, Dustin Strickland wrote:
>>> I usuallly don't do this, but I feel oddly compelled to ask. Over
>>> the past 3 days(and perhaps longer than that, but my logs were
>>> wiped on a reboot) I've been getting failed SSH login attempts in
>>> my logs from a bunch of different IPs in the range
>>> 116.10.191.1-254. I thought this was really unusual; typically,
>>> you'll get a few attempts over the course of 15 minutes to a few
>>> hours from ONE IP, but this has been going on steady for days.
>>> After researching a bit to try to find who owns this network, I
>>> found this:
>>> http://bannedhackersips.blogspot.com/2014/05/fail2ban-ssh-banned-11610191211_7510.html
>>>
>>> `grep 116.10.191. /var/log/auth.log -c` returns 2920. Can you guys
>>> check your logs and post the results(and specultation)? Something