Welcome back spam

 

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By Stuart Turton

Posted on 1 Apr 2009 at 11:44

The spam lull that followed the takedown of the infamous McColo network is over, with spam levels returning to previous highs, according to Google researchers.

By analysing the inboxes of its 15 million business users, Google claims that spam levels returned to pre-McColo takedown levels in the second half of March.

Furthermore, the company says that during the first quarter of this year spam levels grew by 1.2% per day - the highest they've been since early 2008.

McColo was the host for the world's largest spam gangs, but was pulled by its ISPs in November 2008 when they were presented with proof of its involvement in spam rings. According to the Google blog, spam levels "fell off a cliff overnight" plunging by as much as 40%.

However, the researchers suggest spammers have taken steps to ensure there's no repeat of this success: "It's difficult to ascertain exactly how spammers have rebuilt in the wake of McColo, but data suggests they're adopting new strategies to avoid a McColo-type takedown from occurring again," the blog reads.

"Specifically, the recent upward trajectory of spam could indicate that spammers are building botnets that are more robust but send less volume - or at least that they haven't enabled their botnets to run at full capacity because they're wary of exposing a new ISP as a target."

As part of these new tactics, Google says it has seen a rise in spam with malware attached, and attacks tailored to geography and local news.