Re: Server Attack

[Jiri Slaby <jirislaby@gmail.com>]

Jeffrey V. Merkey wrote:
> altendew wrote:
>
> > Hi someone is currently sending requests to our server 20x a second.
> >
> > Here is what one of the logs look like.
> >
> > [CODE]
> > Host: 84.77.19.46   /signUp.php?ref=1945777   Http Code: 403  Date: 
> > Aug 27 17:44:38  Http Version: HTTP/1.0  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; MTQ; PPC Mac OS 
> > X; en-US) AppleWebKit/578.4
> > (KHTML, like Geco, Safari) OmniWeb/v643.68e=C: 
> > Host: 82.234.98.65   /signUp.php?ref=ec0lag   Http Code: 403  Date: 
> > Aug 27 17:44:38  Http Version: HTTP/1.0  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; CDB; PPC Mac OS 
> > X; en-US) AppleWebKit/126.0
> > (KHTML, like Geco, Safari) OmniWeb/v554.35 
> > Host: 84.94.31.161   /signUp.php?ref=ec0lag   Http Code: 403  Date: 
> > Aug 27 17:44:38  Http Version: HTTP/1.0  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; TLD; PPC Mac OS 
> > X; en-US) AppleWebKit/502.6
> > (KHTML, like Geco, Safari) OmniWeb/v401.63ive=C: 
> > Host: 81.49.24.92   /signUp.php?ref=1945777   Http Code: 403  Date: 
> > Aug 27 17:44:38  Http Version: HTTP/1.0  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; SZS; PPC Mac OS 
> > X; en-US) AppleWebKit/230.1
> > (KHTML, like Geco, Safari) OmniWeb/v710.56ive=C: 
> > Host: 80.129.248.17   /signUp.php?ref=1945777   Http Code: 403  Date: 
> > Aug 27 17:44:38  Http Version: HTTP/1.0  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; OST; PPC Mac OS 
> > X; en-US) AppleWebKit/243.6
> > (KHTML, like Geco, Safari) OmniWeb/v846.88 
> > Host: 87.235.49.194   /signUp.php?ref=ec0lag   Http Code: 403  Date: 
> > Aug 27 17:44:38  Http Version: HTTP/1.1  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; SDD; PPC Mac OS 
> > X; en-US) AppleWebKit/430.1
> > (KHTML, like Geco, Safari) OmniWeb/v145.34 
> > Host: 125.129.12.61   /signUp.php?ref=1945777   Http Code: 403  Date: 
> > Aug 27 17:44:38  Http Version: HTTP/1.0  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; WCG; PPC Mac OS 
> > X; en-US) AppleWebKit/455.3
> > (KHTML, like Geco, Safari) OmniWeb/v042.84stemDrive=\x81 
> > Host: 66.110.153.47   /signUp.php?ref=ec0lag   Http Code: 403  Date: 
> > Aug 27 17:44:38  Http Version: HTTP/1.0  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; ZAM; PPC Mac OS 
> > X; en-US) AppleWebKit/387.2
> > (KHTML, like Geco, Safari) OmniWeb/v456.02ve=C: 
> > Host: 62.2.177.250   /signUp.php?ref=ec0lag   Http Code: 403  Date: 
> > Aug 27 17:44:38  Http Version: HTTP/1.0  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; LMZ; PPC Mac OS 
> > X; en-US) AppleWebKit/206.1
> > (KHTML, like Geco, Safari) OmniWeb/v204.07es 
> > Host: 200.115.226.143   /signUp.php?ref=1945777   Http Code: 403  
> > Date: Aug 27 17:44:37  Http Version: HTTP/1.1  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; EDE; PPC Mac OS 
> > X; en-US) AppleWebKit/647.0
> > (KHTML, like Geco, Safari) OmniWeb/v760.47emDrive=C:\x81 
> > Host: 84.171.125.189   /signUp.php?ref=1945777   Http Code: 403  Date: 
> > Aug 27 17:44:37  Http Version: HTTP/1.0  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; QHA; PPC Mac OS 
> > X; en-US) AppleWebKit/778.0
> > (KHTML, like Geco, Safari) OmniWeb/v456.03=C: 
> > Host: 83.242.79.70   /signUp.php?ref=1945777   Http Code: 403  Date: 
> > Aug 27 17:44:37  Http Version: HTTP/1.0  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; GFS; PPC Mac OS 
> > X; en-US) AppleWebKit/537.0
> > (KHTML, like Geco, Safari) OmniWeb/v313.01rive=C: 
> > Host: 86.69.194.172   /signUp.php?ref=ec0lag   Http Code: 403  Date: 
> > Aug 27 17:44:37  Http Version: HTTP/1.0  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; ZCV; PPC Mac OS 
> > X; en-US) AppleWebKit/468.2
> > (KHTML, like Geco, Safari) OmniWeb/v026.14stemDrive=\x81 
> > Host: 196.203.176.26   /signUp.php?ref=ec0lag   Http Code: 403  Date: 
> > Aug 27 17:44:37  Http Version: HTTP/1.1  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; BXT; PPC Mac OS 
> > X; en-US) AppleWebKit/840.3
> > (KHTML, like Geco, Safari) OmniWeb/v767.50s 
> > Host: 201.41.241.190   /signUp.php?ref=1945777   Http Code: 403  Date: 
> > Aug 27 17:44:37  Http Version: HTTP/1.0  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0 (Macintosh; TYZ; PPC Mac OS 
> > X; en-US) AppleWebKit/742.0
> > (KHTML, like Geco, Safari) OmniWeb/v715.65C: 
> > Host: 200.84.144.234   /signUp.php?ref=ec0lag   Http Code: 403  Date: 
> > Aug 27 17:44:37  Http Version: HTTP/1.1  Size in
> > Bytes: -   Referer: -   Agent: Mozilla/5.0  [/CODE]
> >
> > We are currently blocking this user through our Apache.
> >
> > .htaccess
> > [CODE]
> > RewriteEngine On RewriteCond %{HTTP_USER_AGENT} ^Mozilla/5\.0\ 
> > \(Macintosh;\ (.+)\ PPC\ Mac\
> > OS\ X;\ en-US\)\ AppleWebKit/(.+)\ \(KHTML,\ like\ Geco,\ Safari\)\
> > OmniWeb/v([0-9]+).([0-9]+)(.+)$
> > RewriteRule .* - [F]
> > [/CODE]
> >
> > That works fine and is giving the user a 403 (Forbidden), but the 
> > problem is
> > that half of our Apache processes are from this user.
> >
> > Is there a way to block his user agent before he gets to Apache? 
> > Sometimes
> > this brings our server to a crash.
> >
> > Thanks
> > Andrew
> >  
> iptables -J drop <ip address>

Too slow, iptables' rules are (or was, at least) traversed sequentially. Better 
is routing table with blackhole-rule used for these IPs.

Problem is, that IPs are variable, but use of some scripting solves this...

regards,
--
http://www.fi.muni.cz/~xslaby/            Jiri Slaby
faculty of informatics, masaryk university, brno, cz
e-mail: jirislaby gmail com, gpg pubkey fingerprint:
B674 9967 0407 CE62 ACC8  22A0 32CC 55C3 39D4 7A7E
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