Botnet Takedowns Lead to Lower Spam Levels in November

Bredolab and Koobface Botnet Takedowns Lead to Lower Spam Levels in November 

Fortinet’s November 2010 Threat Landscape Report shows a 12 percent reduction in global spam in November after Dutch authorities took down the Bredolab network by taking more than 140 servers offline.

“Bredolab was often used to load spam engines, which are typically used to sell fraudulent pharmaceuticals,” said Derek Manky project manager, cyber security and threat research at Fortinet. “The scale of this Bredolab botnet had a huge impact on spam levels, dropping as much as 26 percent one week after it was dismantled.”

Additionally, Koobface, a botnet well known for spamming popular social media sites, was temporarily taken offline on November 14 when UK ISP provider Coreix was abe to kock out three command and control servers and take them offline. Koobface used intermediary servers (proxies) to communicate with these command and control servers through HTTP port 80. A recent report suggested that the Koobface botnet generated more than $2 million between June 2009 and June 2010.

“We confirmed that on November 14, when the primary servers were taken offline, the intermediary servers failed to proxy content, which effectively crippled the botnet,” Manky continued. “Unfortunately, we saw communication restored five days later on November 19th. This is likely due to the fact that Koobface contains an FTP harvesting module.”  With the FTP harvesting module, botnet operators can use stolen FTP credentials to hijack Web servers for intermediary/proxy use. By reconfiguring their intermediary servers to new command and control servers, the Koobface operators regained control of their botnet.

The full November Threat Landscape report, which includes the top threat rankings in several categories, is available here.