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Desperately need help - CBL Listing

Guest smitty

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Guest smitty

Hello All


I am desperately looking for some direction. I have a Mandriva box with two network cards. One for loc and one for net. Every now and then and it is adhoc we are getting listed on CBL with the following description:


This IP is infected (or NATting for a computer that is infected) with the Conficker A or Conficker B botnet.


It is referring to IP


Is there in which I can block any and all traffic to this IP using shorewall?


I have squid, postfix, shorewall in place. Apparently according to CBL it uses port 80, here we have a transparent proxy in use.


Could anyone please help me out. Have battled for two weeks.


Thank you



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I don't use shorewall, so can't tell you specifically. I am using iptables however, so you should be blocking all inbound traffic unless you need access on those ports. You don't list your inbound requirements. You have squid and postfix, so do these need to be accessible to the internet? If yes, then secure squid so that nobody can use it unless you authorise them to, and the same with postfix:




that page will help you test and tell you what you need to do and fix postfix. As for the rest, you need to generate iptables or shorewall rules to block what you don't want access to. If you want to block on that particular IP:


iptables -A INPUT -d -j DROP


assuming that is your public IP address assigned to this server. If not, replace it with your public IP address. Because the one above that you mentioned is Fremont, California, and your IP posting here is South Africa. So change that destination IP appropriately.


will be suffice, and allow you to continue using your server locally. However it won't be accessible now from the internet for any of your resources. If you need access, then generate appropriate iptables rules prior to this to grant access for particular source IP's, or secure squid so that only authorised users can use it.


Based on the text from the cbl, someone is using your proxy to hide their conficker requirements, and so you were correctly blocked.

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