According to spam experts, zombie computers are the latest wave of terror plaguing e-mail users at Yale.
The number of spam e-mails that Yale Information Technology Services filters out of Webmail each month has risen dramatically since the beginning of the summer, quadrupling to nearly 100 million e-mails a month. Between May and August, spam e-mails as a percentage of total e-mail has gone up from 65 to 87.4 percent.
ITS employees said the spike in the overall number of spam e-mails is due to the heightened summer activity of zombie computers, machines that literally have been possessed by viruses and commanded to send spam over the Internet without their owners’ knowledge. This overall increase may be responsible for the dramatic rise in the number of e-mails caught in Yale filters, they said.
John Coleman, Yale’s e-mail systems administrator, said this summer’s increase in spam volume — a trend that took place all over the world — was due to many zombie computers that became more active when students left campus. The greater number of spam e-mails that the Yale filters are catching is mainly due to this overall increase, not to an extremely new approach on Yale’s part, he said.
“We’ve been catching [the worldwide rise in spam],” Coleman said. “It’s not that we put in a magic filter.”
Despite the lack of the magic filter, Coleman said that ITS uses “a layered approach” to detect spam e-mails, ranging from a DNS blocklist — a list of known spam senders that stops mail from the spam senders from even entering the Yale network — to specific spam software and anti-virus programs.
“[General spam programs] tend to work better … [because] they can be adapted to the problems that are occurring,” he said.
Coleman said students can also take steps to curb the problem. The filter settings that students set for their own e-mail accounts determine the amount of spam e-mails that they receive. But filters are already in place in Yale Webmail accounts, which prevents the majority of spam from entering students’ inboxes, he said.
“You can turn it off if you wish, but we don’t recommend that people turn it off,” Coleman said.
He explained that suspected spam e-mails are assigned a number based on the potential threat they pose, and Webmail users can subsequently choose a filter level corresponding to the assigned spam numbers.
Students said they do not consider spam to be a significant problem in their daily lives. David Porter ’10 said although he would prefer not to receive spam, he does not think it is overly problematic.
“Some of it the junk mail filter gets, and the rest it takes two seconds to delete,” he said.
But Porter said it can be annoying when Yale students use group panlists to promote unrelated agendas.
A further complication in Yale’s fight against spam arises when spammers not affiliated with Yale use University group panlists to send junk mail to students.
Zharna Shah ’10 said she sometimes receives several spam e-mails a day through various panlists.
“I can understand how other students would be upset because they take a lot of time to reach out through their panlists to other students, and this just becomes a big nuisance,” she said.
A student with computer expertise, who asked to remain anonymous, said ITS general filters are doing a reasonably good job, especially considering students’ individual e-mail preferences.
Spam filters operate by detecting certain words in e-mail bodies and subject lines, but not by images.
“[ITS] can only do so much, because if you start filtering e-mails that people are supposed to get, then they get pissed,” the student said.
Coleman said ITS is constantly evaluating new and different varieties of anti-spam software to protect Yalies, but that students should know increased spam is not a phenomenon unique to the University.
“Yale is not under attack,” Coleman said. “It is just that the world is more full of spam.”