Spam grew by 4.9 percent in January, according to MessageLabs' first report since its acquisition by Symantec.
The recent spike returns spam levels almost to the point where they were before the McColo Corp.'s servers were shut down in November 2008. Before its servers were unplugged, McColo was responsible for 80 percent of the spam sent over a four-week period.
Among the top 10 botnets responsible for distributing spam, Mega-D (Ozdoc) had the highest throughput in January, sending more than 26 million spam e-mails per minute.
Cutwail (Pandex) remains the largest botnet with more than one million active IPs this month. Among the top 10 are some new players, including Xarvester, Donbot and Waledac.
MessageLabs also noticed that spam e-mails featuring penny stocks, the inauguration of President Barack Obama, and the conflict in Gaza were popular in January.
"Just one month into 2009 and the threat landscape already appears to be in full swing," said Paul Wood, MessageLabs analyst said. "Toward the end of 2008, the MessageLabs Intelligence team predicted a botnet renaissance in which the cyber criminals would improve the technology behind their botnets, creating a new vanguard. Based on the increase in power, numbers and new bots, the cyber criminals seem to be living up to the prediction."
The penny stock spam is particularly worrisome, considering spammers could swindle people more easily with the promise of "low risk, big return" penny stocks as credit continues to dry up, says MessageLabs.