Re: [squid-users] Squid Proxy Hijacked By Hackers in China

Thanks very much! So, would my configuration file look like this (btw, I'm using Squid2.6.STABLE1, is that a problem?):

http_port XXX.XXX.XXX.XXX:80 defaultsite=www.mysite.com vhost

cache_peer 127.0.0.1 parent 80 0 no-query originserver name=server_1 login=PASS
acl mydomains dstdomain .mysite.com mysite.com
cache_peer_access server_1 allow mydomains
cache_peer_access server_1 deny all

hierarchy_stoplist cgi-bin ?

acl QUERY urlpath_regex cgi-bin \?

cache deny QUERY

acl apache rep_header Server ^Apache

broken_vary_encoding allow apache

access_log /var/log/squid/access.log squid

debug_options ALL,1 33,2

hosts_file /etc/hosts

url_rewrite_host_header off

refresh_pattern ^ftp: 1440 20% 10080

refresh_pattern ^gopher: 1440 0% 1440

refresh_pattern . 0 20% 4320

acl all src 0.0.0.0/0.0.0.0

acl manager proto cache_object

acl localhost src 127.0.0.1/255.255.255.255

acl to_localhost dst 127.0.0.0/8

acl Safe_ports port 80 # http

acl Safe_ports port 21 # ftp

acl Safe_ports port 443 563 # https, snews

acl purge method PURGE

acl port80 port 80

acl CONNECT method CONNECT

http_access allow manager localhost

http_access deny manager

http_access allow purge localhost

http_access deny purge

http_access deny !Safe_ports

never_direct allow mydomains
http_access allow mydomains
http_access deny all

http_reply_access allow all

icp_access allow all

visible_hostname www.mysite.com

coredump_dir /var/spool/squid

--- On Tue, 5/27/08, Amos Jeffries <squid3_at_treenet.co.nz> wrote:

> From: Amos Jeffries <squid3_at_treenet.co.nz>
> Subject: Re: [squid-users] Squid Proxy Hijacked By Hackers in China
> To: badaboom003-asdf_at_yahoo.com
> Cc: squid-users_at_squid-cache.org
> Date: Tuesday, May 27, 2008, 5:00 AM
> badaboom003-asdf_at_yahoo.com wrote:
> > Hi,
> >
> > My server was brought down by a group in China who
> were able to use my squid proxy to send and receive
> requests from their IPs. There were over 370 IPs hitting my
> server. I'm wondering where I went wrong and what I need
> to fix to prevent this in the future? Below are a snippet
> from my cache.log and my squid.conf file with IP
> obfuscated. One thing I noticed was that they connected
> through port 443, which I have in my Safe_Ports list.
> Should I remove all of those ports from my safe list?
> >
> > Any help would be greatly appreciated. Thanks,
> >
> > Chris-
> >
> >
> > My cache.log file
> > =================
> > 2008/05/27 01:36:21| The request CONNECT
> 205.188.153.121:443 is DENIED, because it matched
> 'all'
> > 2008/05/27 01:36:21| The reply for CONNECT
> 205.188.153.121:443 is ALLOWED, because it matched
> 'all'
>
> The CONNECT attempt was blocked. What you see there being
> 'ALLOWED' is
> the denial 404 response going out to whomever tried it.
>
> > 2008/05/27 01:36:21| The request GET
> http://ad.media-servers.net/st?ad_type=pop&ad_s...ed_pop_types=29&pop_times=1&pop_frequency=0$
> > 2008/05/27 01:36:22| The request GET
> http://ad.media-servers.net/st?ad_type=pop&ad_s...ed_pop_types=29&pop_times=1&pop_frequency=0$
> > 2008/05/27 01:36:22| The request GET
> http://202.86.6.132/config?.redir_from=?&.tries=...ntl=us&.bypass=&.partner=&.chkP=Y&.done=ht$
> > 2008/05/27 01:36:22| The reply for GET
> http://ad.media-servers.net/st?ad_type=pop&ad_...size=053&banned_pop_tyimes=1&pop_frequency$
> > 2008/05/27 01:36:22| The request GET
> http://www.clickclickclick.com:80/default.asp is ALLOWED,
> because it matched 'port80'
>
> This is the key bit. You blanket accept on port 80.
>
> > 2008/05/27 01:36:22| The request GET
> http://203.209.228.245/isp_verify_user?l=_Dave_M_&p=ty
> is ALLOWED, because it matched 'port80'
> > 2008/05/27 01:36:22| The request POST
> http://fly.emirates.com/IBE/SearchAvailability.aspx is
> ALLOWED, because it matched 'port80'
> > 2008/05/27 01:36:22| The request GET
> http://edit.in.yahoo.com/config/loginpasswd=23131&.save=1
> is ALLOWED, because it matched 'por$
> > 2008/05/27 01:36:22| The request GET
> http://fly.emirates.com/ is ALLOWED, because it matched
> 'port80'
> > 2008/05/27 01:36:22| The reply for GET
> http://ad.media-servers.net/st?ad_type=pop&adtion=24_pop_types=29&pop_times=1&pop_frequency$
> > 2008/05/27 01:36:22| The request POST
> http://fly.emirates.com/IBE/SearchAvailability.aspx is
> ALLOWED, because it matched 'port80'
> > 2008/05/27 01:36:22| The request POST
> http://mihen.info/Res/CheckProxy.php is ALLOWED, because it
> matched 'port80'
> > 2008/05/27 01:36:22| The request GET
> http://fly.emirates.com/ is ALLOWED, because it matched
> 'port80'
> > 2008/05/27 01:36:22| storeLateRelease: released 0
> objects
> > and on and on...
> >
> >
> > My Squid Config File:
> > =====================
> > http_port XXX.XXX.XXX.XXX:80
> defaultsite=www.mysite.com vhost
> > cache_peer 127.0.0.1 parent 80 0 no-query originserver
> name=server_1 login=PASS
> > cache_peer_domain server_1 .mysite.com mysite.com
> > hierarchy_stoplist cgi-bin ?
> > acl QUERY urlpath_regex cgi-bin \?
> > cache deny QUERY
> > acl apache rep_header Server ^Apache
> > broken_vary_encoding allow apache
> > access_log /var/log/squid/access.log squid
> > debug_options ALL,1 33,2
> > hosts_file /etc/hosts
> > url_rewrite_host_header off
> > refresh_pattern ^ftp: 1440 20% 10080
> > refresh_pattern ^gopher: 1440 0% 1440
> > refresh_pattern . 0 20% 4320
> > acl all src 0.0.0.0/0.0.0.0
> > acl manager proto cache_object
> > acl localhost src 127.0.0.1/255.255.255.255
> > acl to_localhost dst 127.0.0.0/8
> > acl SSL_ports port 443 563 # https, snews
> > acl SSL_ports port 873 # rsync
> > acl Safe_ports port 80 # http
> > acl Safe_ports port 21 # ftp
> > acl Safe_ports port 443 563 # https, snews
> > acl Safe_ports port 70 # gopher
> > acl Safe_ports port 210 # wais
> > acl Safe_ports port 1025-65535 # unregistered ports
> > acl Safe_ports port 280 # http-mgmt
> > acl Safe_ports port 488 # gss-http
> > acl Safe_ports port 591 # filemaker
> > acl Safe_ports port 777 # multiling http
> > acl Safe_ports port 631 # cups
> > acl Safe_ports port 873 # rsync
> > acl Safe_ports port 901 # SWAT
> > acl purge method PURGE
> > acl port80 port 80
> > acl CONNECT method CONNECT
> > http_access allow manager localhost
> > http_access deny manager
> > http_access allow purge localhost
> > http_access deny purge
> > http_access deny !Safe_ports
> > http_access deny CONNECT !SSL_ports
> > http_access deny to_localhost
> > http_access allow port80
> > http_access allow localhost
> > http_access deny all
> > http_reply_access allow all
> > icp_access allow all
> > visible_hostname www.mysite.com
> > coredump_dir /var/spool/squid
> >
>
> It's situations like these is why I always recommend
> using ACL to
> crontol the accelerator/reverse proxy access.
>
> The problem was your "http_access allow port80" -
> thats a blanket accept
> of any request going to *any* webserver.
>
> You would do well to add an ACL listing your domain names:
>
> acl mydomains dstdomain .mysite.com mysite.com
>
> and using it to control both the peer access and the
> acceptable
> requests. Like so:
>
> # pass accelerated domains to the peer
> cache_peer_access server_1 allow mydomains
> cache_peer_access server_1 deny all
> # keep DNS out of the equation.
> never_direct allow mydomains
> # prevent access through the proxy to anywhere else
> http_access allow mydomains
> http_access deny all
>
> instead off all these (adding to the config in their
> position would be
> good):
> > http_access deny CONNECT !SSL_ports
> > http_access deny to_localhost
> > http_access allow port80
> > http_access allow localhost
> > http_access deny all
>
> It also makes "cache_peer_domain" irrelevant.
>
> Amos
> --
> Please use Squid 2.7.STABLE1 or 3.0.STABLE6
Received on Tue May 27 2008 - 18:00:07 MDT