Srizbi Is World's Largest Botnet At The Moment

"The prodigious Srizbi botnet has continued to grow and now accounts for up to 50 percent of the spam being filtered by one security company", says PC World's article. Estimated amount of spam currently sending out daily is about 60 billion spam messages.

"Srizbi is the single greatest spam threat we have ever seen. At its peak, the highly publicized Storm botnet only accounted for 20 percent of spam. Srizbi now produces more spam than all the other botnets combined." said Bradley Anstis from security company Marshal. What has probably made Srizbi so successful is that it appears to spread by as part of the spam messages it sends, meaning that its lifecycle extends to reproducing itself and not just distributing email.

Microsoft told recently about its success combating the Storm botnet with their Malicious Software Removal Tool (MSRT) and now Anstis expects it to turn its sights on Srizbi and the other major botnets.