Symantec Case Study – USA.NET Reduces Image-Based Spam

USA.NET, a message service hosting provider, saw the quality of its message services threatened by a jump in image-based spam in late 2006. Symantec analysts developed new tools and techniques for an antispam solution that more than quadrupled the catch rate for image-based spam. This virtu­ally eliminated it from USA.NET customer mailboxes, ending complaint calls from customers about spam, and helping to reduce the processing and storage burden from image based spam by as much as 95 percent. Download an ESG Lab Review white paper on Symantec Brightmail AntiSpam.

Just Press “Send”

Available, secure, cost-effective email is a price of entry for doing business today. USA.NET, a global electronic messaging service provider, fills this need so well it is the lead­ing exclusively-focused hosted email provider in the United States. The company serves over 1,300 corporate customers including such industry leaders as United Airlines and Farmers Insurance.

One reason for its broad customer base is quality of service. USA.NET has been named the 2006 “Top Player” in the hosted email provider space by The Radicati Group, Inc. It is also SAS 70 Type II audited, a Microsoft Gold Partner, a member of the Microsoft Technology Adoption Program for Exchange 2007, and winner of the 2006 Microsoft Excellence Award for Hosting Solutions.

Dan Wills, USA.NET’s vice president operations, explains the company’s value propo­sition: “Our Hosted Microsoft Exchange and CMS email solutions provide reliability, security, and scalability backed by a commitment to operational excellence. Since our solutions are modular and scalable, our customers can grow their business without having to invest additional resources, time or capital into their mission-critical mes­saging infrastructure.”

Customers can choose from three tiers of Microsoft Exchange Hosting service, and all include spam and virus protection, multiple secure access methods, and a 99.9% SLA for guaranteed uptime.

A Picture can be Worth a Thousand Problems

In the second half of 2006, however, the quality of email service for USA.NET cus­tomers and email users everywhere became degraded by a surge in image-based spam. This is spam consisting of an image with embedded text employed as a trick to by­pass text-based spam filters.

The tactic became dramatically more effec­tive in 2006 when new high-performance software became available that can rapidly generate messages with randomized im­ages. The images are just different enough to fool filters that attempt to detect and block large groups of uniform messages.

Spammers have exchanged this new author­ing software in underground marketplaces and are using it to push out millions of unique spam messages every hour.

The actual work of generating image-based spam is typically done by botnets, or net­works of compromised computers driven from remote locations. By one estimate, more than 150 million computers (or one out of every four PCs connected to the Internet) could be infected by Trojans al­lowing them to be remotely driven for illicit purposes.*

By December of 2006, image-based spam generated by botnets had jumped from representing 10 percent of all spam just six months before to becoming 35 percent of all spam, as estimated by analysts on the Symantec Brightmail AntiSpam team. Download an ESG Lab Review white paper on Symantec Brightmail AntiSpam.

Everyone is Hurt

This increase in image-based spam penal­izes email users and companies in two ways: More spam evades filters and reaches inboxes, forcing users to lose precious time sorting messages and deleting spam. And because image-based messages are often five to seven times larger than text-based spam, they put an unexpected and costly burden on email server processing time and storage space. Some businesses are forced by regulations to retain every email they receive for a given period of years. For them, the burden is even heavier.

Spam had ceased to be a problem at USA.NET when it implemented Brightmail AntiSpam software in 2002, before the emergence of image-based spam and be­fore Brightmail was acquired by Symantec. “At that point, spam virtually disappeared and everybody forgot about it,” says Jen­nifer Angle, senior marketing director at USA.NET.

The company has been successful using a three-layered approach to fight spam. On the outside are appliances that deny con­nections to known spammers. “On a given day, we’ll block over 40 million attempts to connect from known spammer IPs,” Wills says. A second layer is proprietary software that performs behavioral analysis on incoming messages and blocks them if it detects spam-like behavior. “These first two layers stop 85 percent of spam,” Wills says. “Symantec Brightmail is at the third layer, filtering out what gets through.”

In late 2006, however, image spam started appearing in the inboxes of USA.NET cus­tomers. High level executives at some of the company’s most prominent accounts were particularly disturbed at having to delete spam once again. A number of them called USA.NET to complain, and the com­pany relayed their concerns to the team at Symantec Brightmail.

Setting Out to Turn Back the Tide

With customers such as USA.NET and mil­lions of other companies in mind, analysts at Symantec Brightmail developed new techniques for detecting image-based spam, and new kinds of rules that block it. They increased the frequency of updates to Brightmail regarding image spam heuristics from weekly to daily. This countered the fact that spammers were speeding up the fre­quency with which they test, enhance, and modify their image-based spam tactics.

The new enhancements for Symantec Brightmail AntiSpam became available in release 6.0.4, reaching customers in the fall of 2006.

The Brightmail catch rate for image-based spam, as measured by the Brightmail team, jumped from 20 percent to 95+ percent—a more than a fourfold gain in effectiveness. Read an email hosting press release for more information.

At USA.NET, image spam disappeared from executives’ inboxes. “From what we’re seeing,” says Wills at USA.NET, “the catch rate is even higher than that.” Complaint calls about spam from executives at the company’s customers stopped.

One USA.NET customer that appreciated the change was Hellmuth, Obata + Kassabaum, Inc. (HOK), a global architectural leader with 2,000 architects in North America, Latin America, Europe, and Asia. “Last fall, it seemed we went from one spam message a week in inboxes to one a day,” says Ken Young, senior vice president and chief in­formation officer at HOK. “Spam went from nothing to being an annoyance—but then it stopped.”

Even one spam message a day has an im­pact. It takes an employee about three sec­onds to identify and delete it. That may not seem like much, but multiply three seconds a day by 2,000 architects and HOK gains $17,000 a year in productivity by prevent­ing this interruption.**

“I was just part of a C-level roundtable put on by an industry magazine,” Young says, “and the panelists started to talk about how much time it took to fight image-based spam and how much was getting through. I sym­pathized, but didn’t participate in the topic because we don’t even have spam—much less a spam problem—thanks to USA.NET.”

Reeling in Phishing Attempts

In addition to blocking spam, Brightmail protects USA.NET customers by detecting phishing emails received at over two million decoy email accounts in Symantec’s Global Intelligence Networks. Then Brightmail updates its filters worldwide via Symantec LiveUpdate to block these messages.

Stopping phishing attempts provides added value. At one USA.NET customer, a senior executive had mistakenly responded to a phishing email before subscribing to USA.NET and Brightmail. As a result, the execu­tive had to divert his IT security team to per­form the many hours of work it takes to clear up a case of identity theft. According to ex­ecutives at USA.NET, this customer is espe­cially appreciative that virtually no phishing attempts are reaching users today.

Brightmail has a 99.8 percent accuracy rate, according to one study.*** Most custom­ers new to USA.NET start with Brightmail cautiously by having it flag rather than block spam. “Within days, they see that Brightmail is stopping only spam, and they switch from ‘flag’ status to ‘delete’ status,” says Wills.

Spam You’ll Never See

“Our customers are grateful that image spam is blocked. That’s a key service dif­ferentiator for USA.NET and it’s due to our multi-layer antispam solution that includes Symantec Brightmail,” says Victor Silva, director of client services. “Our customers read in the media that image spam is afflict­ing most companies, yet they know it’s not reaching them. This is a valuable benefit for us in maintaining customer satisfaction and retention.” USA.NET has one of the highest renewal rates in the hosted email industry, Silva points out.

Another benefit is that with image spam blocked, customers require less email stor­age space. Spam makes up as much as 95 percent of the incoming email stream for USA.NET customers, the company reports, and because Brightmail and USA.NET’s multilayer approach successfully blocks it, the demands on email infrastructure are substantially reduced. “Our customers may be paying as little as 10 percent of the message infrastructure costs they’d face if spam wasn’t blocked,” says Wills.

Download an ESG Lab Review white paper on Symantec Brightmail AntiSpam.

Exchange Hosting Services:

* “Botnets could eat the Internet” at, from a speech by Vincent Cerf, one of the founders of the Internet, at the World Economic Forum in Davos, Switzerland, published Friday, January 26th, 2007.

** 3 seconds/day * 2,000 employees*250 work days/year = 1.5 million seconds/year = 25,000 minutes = 417 hours lost to spam* $40 per hour burdened labor rate= $17,000 in annual productivity lost to just one spam message per day.

$40 burdened labor rate determined as follows: $60,000 an­nual median salary for U.S. architects per the U.S. Department of Labor Bureau of Labor Statistics Occupational Handbook. Add 1/3rd for benefits to arrive at $80,000 annual burdened labor cost/ 2,000 hours per year = $40 per hour burdened labor rate.

*** GCN report, 2006

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