NEWS

BY EDUARTO OTERO

Cleveland State University e-mail system by the Information Service & Technology Division did not feature any modifications to the occasionally bothersome spam filter.

The upgraded system operates separately from the university’s security filter that regulates spam, according to IS&T staff. The filter is maintained by two security administrators.

Some faculty members, like communication professor Dr. Anup Kumar, are nonetheless weary of the filter’s accuracy.

Kumar, like many CSU instructors, relies largely on the virtual back-and-forth interaction made possible by e-mail in recent decades.

Surprisingly, however, he is more concerned about what the spam filter doesn’t let into his inbox than what it does.

What Kumar finds is that the filter quarantines legitimate e-mails along with malicious ones, impeding the reception of important materials, such as student inquiries and assignments.

Such discrepancies are inevitable, said IS&T Security Administrator Michael Holstein.

“On any given day, we process around 2 million e-mails,” Holstein said. “About 95 percent of that is junk, one way or another.”

Spammers have become increasingly innovative and aggressive since the inception of electronic messages, using techniques such as directory harvest attacks, or forceful attempts to discover valid e-mail addresses at particular domain names, said Holstein.

Holstein called the system effective despite a few nuisances, which he attributed to the kinds of shortcomings that typically occur when a machine attempts to perform what humans would consider to be a straightforward task. “When spammers first started sending messages about Viagra and Cialis, they would just put those words in the message,” Holstein said. “We caught on to that quickly and so they started sending mail with numbers and symbols replacing letters in text.”

Adapting the filter to accommodate suspicious terms that incorporate symbols and numeric digits prompted spammers to additionally employ alternative tactics, such as embedding words into images, thus bypassing the system’s detection of questionable text.

“It’s a cat-and-mouse game,” he continued, “a never-ending battle.”

The spam filter’s painstakingly thorough fine-tuning over the years to include an immense assortment of criteria in an attempt to identify and block unsolicited mail has, unfortunately, led to the inadvertent identification of genuine messages as spam.

Nonetheless, Holstein said that these cases of mistaken identity were marginal in comparison to the filter’s efficiency weeding out actual spam.

“Some of it still gets through, [but] we do catch the majority of it,” Holstein added.
“It’s not a perfect process.”

Holstein said that CSU e-mail users have the ability to change their settings and regulate the potency of the filter to meet an individual’s needs, since the amount of junk mail received can vary from user to user.

Those users hardest hit can receive up to 5,000 spam messages per day, but the majority of those messages are obstructed by the system’s default settings, he said.

Users also have the capability to release messages inaccurately labeled as spam, which automatically labels their senders as safe for future corresponding. Those senders are added to a white list, after which their mails are no longer filtered as junk.

“Spam has become a commercial enterprise,” Holstein said.

“It has continued to increase year after year,” he continued. “When we first implemented the filter, we were [only] dealing with a couple of hundred thousand messages per day.”

The spam filter operated by Information Security is a commercially-supported solution.

It is managed by SonicWALL Email Security, whose signatures are updated every 30 minutes by more than 600 employees around the world to include new potential threats.

Most spam emanates from botnets, or groups of compromised computers functioning autonomously, but there is no one source that can be blamed for the vast majority of it, Holstein said.

Despite this, many botnets using English translators are controlled out of post-Soviet countries in Eastern Europe, such as Ukraine. Still, spammers are not limited to this region.

Holstein referenced the case of McColo, a San Jose, Calif.-based web hosting service provider that was shut down late last year for trafficking large amounts of malware, or malicious software designed to infiltrate and damage a computer system, via botnets.

The global spam volume was reduced by nearly half after McColo’s upstream providers disabled its servers. However, spam levels are now back to what they were prior to McColo’s takedown, he said.

“No legitimate organization, be it your bank, a merchant, or the university, will ever request your password or financial details over e-mail,” Holstein warned. “Nobody does that.”

Posting an e-mail address on the CSU Web site, as many professors do, for example, can make it vulnerable to malevolent scripts that “scrape” addresses from the Internet, increasing the likelihood of receiving spam.

Signing up for newsletters and mailing lists is not a good idea either, Holstein said, as they get sold and passed around among spammers.

For now, Kumar takes special care not to disclose his address to Web sites in order to avoid spam, adding, “I have several different e-mail accounts.”

But for Holstein, the future of e-mail looks potentially bleak.

“It is becoming a harder and harder problem to address,” he said. “Eventually it may reach the point where e-mail becomes unusable as a communication medium because the signal to noise ratio is so bad.”