From: IT World —

Spam levels are rising again across the Internet, following the dramatic take-down of major spam host McColo in San José, CA, last week.

At that time, Internet traffic monitors recorded an 80 per cent drop in spam volumes worldwide. But, even then, they warned that such levels would not hold. And, now, just a couple of weeks later, they report that spam traffic is on the rise again.

As IT World’s Jeremy Kirk reports, “Computers that are part of the Srizbi botnet — which by some estimates sent nearly half of the world’s spam — are apparently becoming active again, according to researchers… Srizbi’s computers were controlled by spammers through McColo’s network. When McColo was shut down, those computers tried to call back and get new instructions to send spam. But the botnet operators are clever and created a way to get those machines back if they were stranded.”

In fact, researchers say that at least four major spam networks, believed to be collectively responsible for up to three quarters of the world’s total spam, are now back on the air again.