Klez: Don't Believe 'From' Line
From Wired News
Story location: http://www.wired.com/news/technology/0,1282,52174,00.html
02:00 AM Apr. 30, 2002 PT
Some Internet users have recently received an e-mail message from a dead friend. Others have been subscribed to obscure mailing lists. Some have lost their Internet access after being accused of spamming, and still others have received e-mailed pornography from a priest.
These ersatz e-mails containing the virus are creating Klez-provoked arguments and accusations that are now spreading as fast as the worm itself.
The latest variant of the Klez virus started spreading 10 days ago. The virus e-mails itself from infected machines using a bogus "From" address randomly plucked from all e-mail addresses stored on an infected computer's hard drive or network.
Recipients of the virus-laden e-mails, not understanding that the "From" information is virtually always phony -- or even that they have received a virus -- have been clogging networks with angry and confused e-mails that are causing a great deal of cyber-havoc. People signing up for newsletters and mailing lists that they never subscribed to has been a major source of frustration for both users and the list owners.
If Klez happens to send an e-mail "from" a user to an e-mail list's automatic subscribe address, the list software assumes the e-mail is a valid subscription request and begins sending mail to the user.
A mailing list for fans of the Grammy Award-winning Steely Dan band has posted an explanation directed to those who were subscribed to the list by the virus.
"We are not infected with the Klez virus. We don't know if you are infected with the Klez virus. You may be. But even if you are not, someone out there is infected and has both your address and our address on their computer ... and therein lies the problem," the explanation reads, in part.
Even when users understand the source of newsletter-generated e-mails, the amount of mail some lists generate is causing problems.
"Last week I suddenly started getting hundreds of e-mails, daily, with information about raising tropical fish, purchasing cosmetics and staying in youth hostels," Victor Montez, a sales rep for a publishing firm, said. "I do not keep fish, wear makeup or travel rough."
Montez now understands the e-mails came from Klez-subscribed news lists. But he said that since his free e-mail account only stores a certain amount of messages, he's lost access to the account twice this week. He believes he's also lost a significant amount of business-related e-mails.
In some cases, it almost seems as if Klez is specifically targeting particularly vulnerable e-mail addresses onto which it can piggyback.
E-mails containing an invitation to view what purports to be an attachment with pornographic images appears at first glance to have been sent out by Catholic parishes in New York and Maryland. The attachment actually contains the Klez virus, and tracing information indicates the e-mails were actually sent from an Internet service located in the United Arab Emirates.
"While we would obviously never choose to have our churches' names affiliated with such material, this is a particularly difficult time to have e-mail with obscene references -- which appear to have been sent by church staff -- circulating," an archdiocese spokeswoman said, referring to the worldwide sex abuse scandal.
Other newsletter owners are also suffering. Some say their Internet service providers have accused them of spamming non-members. Many ISPs cut service when they receive a certain amount of spam complaints.
"I was reported to my ISP over a dozen times this week for spamming," said Keith Carlone, the manager of an e-mail newsletter for classic car enthusiasts. "My ISP threatened to pull my account after the third complaint and we went down shortly afterwards. It took four days to sort the problem out."
Andrew Fiber, maintainer of a Jewish folk music mailing list, said that the list has been inundated with messages about widely off-topic subjects, so much so that Fiber wondered if most of his members had suddenly gone "meshuga (a little crazy)."
"All of a sudden we had e-mails coming in from around the world, with people yelling we had sent them Klez," Fiber said. "The thing is that 'Klezmer' is a type of traditional folk music which we often discuss on the list and sometimes refer to as Klez. So I thought people were protesting about our folk music. It was very confusing for a while."
"I belonged to a tattoo artists' list that closed down a few years ago. Last week, I began getting e-mails from the list. Even weirder, I got eight e-mails with subject lines that read 'SOS' and 'Eager to See You' from a list member who died last year. It totally creeped me out," said "Bear" Montego. Klez e-mails' subject lines are randomly chosen from a pre-programmed list of about 120 possibilities, including "Let's be friends," "Japanese lass' sexy pictures," "Meeting Notice," "Hi Honey" and "SOS." Klez also sends fake "returned" or "undeliverable" e-mails, advising the supposed sender that their original, refused e-mail is contained in the attachment. Clicking on the attachment triggers the virus. The virus can launch automatically when users click to preview or read e-mails bearing Klez on systems that have not been patched for a year-old vulnerability in Internet Explorer, Outlook and Outlook Express. Klez only affects PCs running Microsoft's Windows operating system.
As of Monday afternoon, Klez's spread seems to have slowed, but antiviral experts warn that the worm will be around for a while.
"Anytime you have a virus that is not easily identifiable visually, it tends to linger," Rod Fewster, Australian representative for antiviral application NOD32, said. "SirCam and Klez both vary the subject lines of the e-mails they send, which makes it hard for the average user to spot."