Sudden massive bot recruitment campaign by Srizbi botnet drives malicious spam up 9.9%, according to researchers at Marshal

A massive bot recruitment campaign appears to be behind a record surge early this month in the volume of malicious spam -- from 3 percent of all spam traffic to nearly 10 percent, according to researchers with  Marshal’s TRACE team .

The Srizbi botnet, which has been making bigger waves these days than the fizzling Storm botnet, is the main driver of this malware-laden spam, according to Marshal, which says malicious spam traffic tripled within just one week. Srizbi is behind nearly half of all spam, malicious or otherwise, according to the researchers.

“When you see a 9.9 percent jump in one week, that’s significant. They either accidentally sent out too much spam or are on an ambitious recruitment drive at the moment,” says Bradley Anstis, vice president of products for Marshal. Anstis says he thinks it’s more the latter.

MX Logic last week reported a worm that had generated over 8 million spam messages in an apparent attempt to recruit bots for Srizbi.