Re: [Full-disclosure] targetted SSH bruteforce attacks

[Cody Robertson <cody@xxxxxxxxxxxx>]

On 6/23/10 12:38 PM, Gary Baribault wrote:
> In this attack, there's no need to throttle, the attacking computers hit
> it once every 15 seconds or so from many different sources. My denyhosts
> is not blocking 99.999% of the attempts.
> 
> Gary Baribault
> Courriel: gary@xxxxxxxxxxxxx
> GPG Key: 0x685430d1
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> 
> 
> On 06/23/2010 12:33 PM, Cody Robertson wrote:
>> On 6/23/10 4:22 AM, yersinia wrote:
>>   
>>> On Thu, Jun 17, 2010 at 4:21 PM, Samuel Martín Moro 
>>> <faust64@xxxxxxxxx>wrote:
>>>
>>>     
>>>> I also don't want to change my ssh port, nor restrict incoming IPs, ... and
>>>> I use keys only to log in without entering password.
>>>> So you're not alone.
>>>> I had my IP changed several times, my servers are only hosting personal
>>>> data.
>>>> But I'm still seeing bruteforce attemps in my logs.
>>>>
>>>> Here's something I use on my servers.
>>>> In cron, every 5-10 minutes, that should do it.
>>>> Of course, if you're running *BSD, pf is way more interesting to do that.
>>>>
>>>> Perhaps could be better to use something standard as fail2ban
>>>>       
>>> http://www.ducea.com/2006/07/03/using-fail2ban-to-block-brute-force-attacks/?
>>>
>>>
>>>
>>>
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>>>     
>> If you have iptables it has ways you can do this throttle too many
>> connections within a specified period. I much prefer using something
>> such as this over third party software.
>>
>> I'm sure you can do this in PF however I'm not familiar with it enough
>> to be certain (I'd be surprised if you couldn't however).
>>
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>>   
> 
> _______________________________________________
> Full-Disclosure - We believe in it.
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It tends to vary for my machines however it still catches quite a bit of
throttling. Regardless it was just a recommendation to avoid using third
party software for something so trivial.

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