Security experts warned Thursday of a fast-spreading email worm, the first large outbreak of this type in nearly a decade.
The worm appears in e-mail messages with the subject "Here you have," and contains what seems to be a link to an Adobe PDF file. In fact the link takes the victim to a web page hosted on the members.multimania.co.uk domain that then tries to download a screensaver (.scr) file. If the user agrees to installing that file, he is then infected by the worm, which mails itself to his e-mail contacts.
It bogged down corporate e-mail systems on Thursday morning as victims ended up inadvertently spamming their coworkers, overwhelming some servers. The SANS Internet Storm Center, a volunteer-run security intelligence organization, received numerous reports of networks being overwhelmed by the worm, according to said Marcus Sachs, a director with the group. "It seems to be in the category of extremely widespread," he said.
ABC News reported that NASA (the National Aeronautics and Space Administration), Comcast, AIG, Disney, Proctor & Gamble, and others had been hit by the outbreak, and several system administrators contacted by the IDG News Service reported significant headaches.
As of Thursday afternoon, the worm was undetected by most antivirus programs, according to the VirusTotal Web site.
The worm is similar to the ILoveYou and Anna Kournikova worms, which spread in 2000 and 2001, and is a type of malware that has not been a major problem since around 2002, according to David Cowings, a senior manager with Symantec Security Response. "It looks like we've had a resurgence of mass-mailing worms," he said.
In fact, "Here you have" is the same subject line used by the Anna Kournikova worm.
This latest worm seems to do nothing more than send itself out, using the victim's contact list, Cowings said. "It appears to be mailing itself to all of the mailing lists that are in someone's contacts. It may also go to individuals," he said. The worm appeared to be affecting Outlook e-mail users, but it's not clear if it is also affecting users of other mail programs.
The worm also spreads by copying itself to the computers' local drives, (C: and H:) as well as well as drives that are shared over the network, Microsoft said in an analysis of the infection, posted Thursday.
The body of the e-mail typically says something like, "Hello... this is the document I told you about, you can find it here." Because the worm is spreading via contact lists, the e-mail often comes from someone the victim knows.
Symantec started blocking the worm at around 10:30 a.m. Pacific Time Thursday and quickly stopped 65,000 messages, according to Cowings. The number soon ballooned beyond that, but the worm may now have a hard time spreading, because the malicious file on multimania.co.uk appears to have been taken down, Cowings said.
Multimania.co.uk is a free website hosting service run by Lycos.
In an alert sent out to customers Thursday, McAfee recommended blocking .scr files at the Internet gateway. "McAfee has received confirmation that some customers have received large volumes of spam containing a link to malware, a mass-mailing worm identified as VBMania," the note reads. "The symptom reported thus far is that the spam volume is overwhelming the email infrastructure."