Posted by Virus Bulletin on Jan 4, 2011
New botnet shares fast flux DNS and other similarities with Storm and Waledac.
In the last few days of 2010, security researchers discovered a new botnet that shares many similarities with the Waledac and Storm botnets.
The botnet started with a spam campaign that sent millions of emails claiming to be holiday e-cards - a well-known trick used to lure users into clicking malicious links, and one that has already been used by Waledac and Storm. The typical email contains a link to a page on a hacked website, and when that link is clicked the user is automatically redirected to a domain controlled by the spammers.
This domain then resolves to the IP address of an infected machine which, among other things, runs a web server and infects the user with a copy of the malware. By using fast flux DNS, the botherders have ensured that the domain will continue to be resolvable if an infected computer is taken down.
A list of the IP addresses of 500 peers is hard-coded in the malware. Every 10 minutes, the bots connect to one of these hosts and each downloads a list of 10 new peers and their IP addresses. This peer-to-peer behaviour makes the botnet less dependent on a centralized command-and-control server.
Detected samples of the malware all have different checksums, but each has a file size of 485,888.
More can be found at Shadowserver here, or at Kaspersky's Securelist blog here.
Posted on 04 January 2011 by Virus Bulletin
