Posted on behalf of Mathew Nisbet, Malware Analyst, Symantec Hosted Services and Matt Sergeant, Senior Anti-Spam Technologist, Symantec Hosted Services
On December 25, 2010, Rustock, the largest of the spam botnets, went quiet. Why this happened, we don't know but what we do know is that global spam levels dropped massively as a result. MessageLabs Intelligence analysts did not expect this respite to last, and sadly we were right.
Since around 00:00 (UTC) on January 10, Rustock has resumed activity, and appears set to continue where it left off on December 25 as the biggest source of global spam.
As Rustock has now returned, this means the overall level of spam has increased. MessageLabs Intelligence honeypot servers have seen an increase of roughly 98 percent in spam traffic between 00:00 and 10:00 today compared to the same period on...