Google has reported a 156 percent increase in the amount of unwanted e-mail spam targeting users of its Postini enterprise system between November 2008 and data from earlier this month, a rapid increase from the 25 percent  annual 2008 rise the Mountain View, California-based Internet giant announced Monday. Google released information from its Postini Message Security network, a group of primarily business e-mail users that receives some 2 billion e-mails daily, which showed that without the sorting and removal of spam its system provides, the average Postini user would have received 45,000 unwanted e-mails during 2008. Rapid Spam Growth Rate Since Notorious Spam Host Knocked Offline The 2008 figure rose from an average of 36,000 unwanted e-mails during 2007 and 22,500 in 2006 that entered the e-mail stream for users of Postini, the e-mail management company with some 300 employees Google purchased in 2007, Google said. "While spam is still down overall, it's important to note its rate of growth," Google message security team member Amanda Kleha wrote in a message posted Monday to the company's enterprise blog. In November 2008 a significant portion of the flow of spam to e-mail accounts the world over was stopped when San Jose-based online services hosting company McColo had its Internet connection shut off by the companies that provided it access, in one of the most disruptive events to ever target the production and distribution of spam. While the information Google released Monday did not contain statistics on spam levels among users of its popular Web-based e-mail system Gmail, the study offered what it said was "strong insight into the state of the spam industry overall," and a glimpse inside one of the largest groups of e-mail users yet, showing a sharp drop in spam levels after McColo lost its upstream Internet provider. Google Blocked Nearly 200 Messages For Each User On Worst 2008 Spam Day "When McColo went offline, we saw spam drop by 70 percent compared with previous levels," Kleha wrote in the Monday blog post, in which she described McColo as a "large source of the world's spam." Some estimates placed the spammers using McColo as serving up as much as three quarters of all Internet spam at the time the hosting company was shut down. Without increased vigilance on the part of e-mail users and stepped-up filtering technology Google warned that  spam levels were likely to return to levels seen before the McColo incident within a few months, and perhaps rise to new record highs. The highest volume of spam targeting Google's Postini users for 2008 came on April 23, when the filtering systems in place at the e-mail firm blocked an average of 194 messages per user that it considered to be spam, Google said. While not changing significantly over the course of 2008, the methods used to trick users into clicking on a link in a spam e-mail or to open an attachment usually carrying a computer virus or other form of malicious software, continued to rely on messages that imitated e-mail coming from trusted sources. Google Reports Spam Levels Rose 25 Percent In 2008 "Spam messages would often try to fool users by mimicking legitimate emails such as package tracking notifications or invoices that included virus attachments," Kleha noted Monday. "Despite eliminating a major source, spam keeps coming back," she added. Spam levels have returned to levels close to those seen before McColo ceased operations, according to a separate new report released Monday by computer security software maker Symantec. Nearly 75 percent of all e-mail examined by Symantec during December 2008 was seen as spam, with only 25 percent legitimate e-mail messages, the security firm report noted in the Monday report. Google said that the volume of computer viruses it measured during the second half of 2008 rose six-fold from totals recorded during the first six months of the year. Related Links:
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