Posted by Virus Bulletin on Nov 13, 2008
Web-hosting firm believed to be responsible for 75% of spam.
Anti-spam researchers across the world reported a significant drop in the volume of spam seen after web-hosting firm McColo was taken offline on Tuesday.
The San Jose, California-based provider is believed to have hosted many botnet control centres that controlled zombies around the world and were responsible for more than 75% of the spam sent globally each day.
Security researcher Brian Kreb, who writes the Security Fix blog for the Washington Post, has spent several months collecting evidence about suspicious activities on the provider's network. Earlier this week he contacted McColo's two major upstream providers who then pulled the plug. Spam levels dropped almost instantly.
Much as a drop in spam is welcomed by system administrators and end users alike, it is very unlikely that this dip will last very long. The zombies that actually sent the spam are still active and unfortunately there are still many providers who are willing to turn a blind eye to the activities their customers are involved with. Once the spammers have found new providers they are likely to start flooding our inboxes again and there is little doubt that December, traditionally the month in which we see the highest volumes of spam, will see spam levels reach record levels again.