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<p class="MsoNormal">I have snort rules that are looking for traffic to certain websites, based upon the IP Address of the destination…
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">However I would like to create a few rules that look for traffic headed to a website that might be using Dynamic DNS (or fast flux) and so I do not know the IP Address of the dst host.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">For the IP Address alerts I use the following rule:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">alert tcp $HOME_NET any -> $MALICIOUS_IP any (msg:"Malicious traffic alert"; flow: established; classtype: policy-violation; priority:669; sid:2009072103; rev:2;)<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Where $HOME_NET is my internal network and $MALICIOUS_IP is the IP Address of a site that we have deemed to be dangerous.  I don’t think that I can put a website name in the variables… and with Dynamic DNS and FastFlux changing the IPs
 I can’t figure out how to alert on malicious sites being hidden behind the changing IP addresses.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Is it even possible?<o:p></o:p></p>
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