UPDATE, Nov 27th: One of the new CnC servers, ’sdx3Fs5B.info’ was resolving to 72.233.114.74 at LayeredTech. FireEye sent an abuse notification to LayeredTech when the CnC servers went online and they have pulled out the server.

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Yesterday, Nov 24, 2008, I noticed a sudden spam rise. When checking some samples I found that the ‘Canadian Pharmacy’ spam is back and some new image based spam campaigns have been launched.

But the ‘Canadian Pharmacy’ spam is where we should focus on. These spam campaigns are being sent by Rustock, so the conclusion is that these guys are back online and in business.

With subjects like Obama.s new plan, Food crisis in California or Bush.s last words they try to get their email opened to see the ‘Canadian Pharmacy’ advertisment. URLs, like hxxp://alsi.kugusup.cn or hxxp://ppbka.kugusup.cn will redirect you to hxxp://beautythrow.com/ where the Canadian Pharmacy web site is hosted.

When looking for more information if Rustock is back I found that the Company FireEye Security has posted more details on their blog.

As expected, the bot admins learned from the shut down of McColo. They can now simply change DNS to make sure that their command and control server still can be accessed.

The new Rustock spam campaign is already having an impact on the spam levels. The image below is the graph for one of my domains and you can see the spam level drop when McColo was taken down. The red line is the global spam level.

We have a peak during the weekend, the absence of business emails, and a global spam level between 75% and 85% during the week. Yesterday we had a spam level of 89,4% and at the time of writting this article we are back at 93%. You can see the graph going up again after the re-activation of the Rustock C&C servers.