Posted by Virus Bulletin on Aug 28, 2009
Spam levels back to normal within a few days.
The take-down of the rogue ISP Real Host on 1 August saw spam levels temporarily drop by more than a third, Messagelabs claims in its monthly Intelligence Report.
The provider, based in Riga, Latvia, was linked with various kinds of malicious activity. In particular, it is believed to have hosted the command-and-control centres of the Cutwail botnet (also known as Pandex or Pushdo), which is responsible for about 15 to 20 per cent of the spam sent out worldwide. After the take-down the total spam levels dropped by 38%.
After Atrivo (InterCage), McColo and Pricewert (3FN), Real Host is the fourth major rogue provider to have successfully been taken down.
In the well-reported case of the McColo take-down, it was several months before spam levels recovered, however in this case it took just three days for spam levels to recover - suggesting that botnets have become less dependent on their ISPs. (It should also be noted that a measured drop in spam levels is not felt the same by everyone.)
In the same report, MessageLabs also discussed the ongoing popularity of URL-shortening services in spam campaigns. On one day in July, more than 9 per cent of all spam contained a shortened URL.
The full report can be downloaded as a PDF here, with comments on the AllSpammedUp blog here and from Damballa's Gunter Ollmann, about the ambiguities involved in measuring botnet sizes, here.
Posted on 28 August 2009 by Virus Bulletin