SecureWorks says botnets can spew out 100 billion spam messages a day

At the RSA Security event taking place this week in San Francisco, I was interested to listen to Joe Stewart's presentation on spam.

Joe, who is director of malware research with SecureWorks, said that there are a lot of botnets out there. So many, in fact, that they are quite capable, he reckons, of infected a million computers on

t'Internet at any given time.

These computers, he says, are capable of generating around 100 billion spam messages a day.

That's a lot of spam.

The botnet at the top of the chart is Srizbi. According to SecureWorks, this botnet - which also goes by the names Cbeplay and Exchanger - as an estimated 315,000 bots and can blast out 60 billion messages a day.

The second-largest botnet is Bobax, which SecureWorks says has an estimated 185,000 hacked systems in its collection. This translates to around nine billion spam messages a day.

Check out more on Joe's presentation here: