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Spam volumes increase to pre-McColo takedown levels

Mega-D botnet spewing out junk mail torrent

Junk mail levels are back to 80-90 per cent of their volumes prior to the takedown of infamous junk mail-friendly ISP McColo in November 2008 last year.

Spam levels are up 4.9 percentage points since December 2008 to 74.6 percent, reaching levels close to those prior to the McColo takedown, according to an analysis by email and web filtering firm MessageLabs published on Monday.

It reports that the Mega-D (Ozdoc) botnet is making the largest single contribution to junk mail levels, sending more than 26m spam emails per minute. Meanwhile, the Cutwail (Pandex) remains the largest active botnet with more than 1m active IPs this month. MessageLabs is yet to see any junk mail from machines compromised by the Conficker worm.

In other spam-related news, security researchers at Trend Micro were surprised to discover that items of dating spam in a recent junk mail run were spoofed so that they appeared to come from the security heavyweight.

But spammers got things badly wrong in the the design of the spam run, which comes in the run-up to Valentine's Day. By tampering with the From field in the messages, junk mailer hoped to sneak their useless messages past spam filters.

However the hackers in this case erred badly, because the From and Reply-To addresser in junk mail messages are spoofed. As a result, "the spammers themselves aren’t getting the replies or even the bounces to the spammed messages they sent," writes Mary Ermitano, an anti-spam research engineer at Trend Micro. "This attack is apparently just a waste of resources for spammers."

The spam run seeks to promote websites while also seeking to validate email addresses for later, possibly more insidious, junk mail runs. The junk mail messages in this case are not in themselves pointed at malware and don't point to malware infected sites - at least not yet.

A full write up of the attack, more of which can be expected to surface on the run-up to Valentine's Day on 14 February, can be found here. ®

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