After Short Break, Storm Worm Fires Back Up With New Tricks

After taking a 13-hour break late last week, the virulent Storm worm is back to its old tricks, trying out new tactics, and taking advantage of the Labor Day holiday.

The malware, which has relentlessly hammered the Internet for the past three months, is being spread this week in mass mailing that portends to be a Labor Day-themed electronic greeting card, according to Vinoo Thomas, a McAfee AVERT Labs researcher.

"The authors have used anchor tags in HTML to mask the greeting card link so that an unsuspecting user does not notice that it actually points to a malicious IP address," wrote Thomas in a blog entry. "Hovering the mouse over this disguised link is a quick and dirty way to reveal the real destination address."

He added that users who click on the link are taken to a Happy Labor Day page. Once there, an "exploit cocktail" is downloaded onto victim computers. "In addition to the usual Microsoft exploits, QuickTime and WinZip buffer overflow exploits are also attempted on a user's machine," wrote Thomas. "Given the slim likelihood of vulnerable third party applications being up to date on a user's machine, it increases the attacker's chances of a successful exploitation. Especially since most applications do not support automated updates and it is left up to the users to first find out if they have a vulnerable version of the application and then manually patch it."

However, the Storm authors are too enterprising to go with just one attack.

They've also been sending out waves of fraudulent e-mail that claims to link users to music videos of pop stars like Beyonce Knowles, Kelly Clarkson, and Rihanna. According to researchers at Sophos, the subject lines include: awesome new video, Cool Video is out, dude this is not even on MTV yet and this video rocks. Other musicians referenced include The Eagles, Foo Fighters, R. Kelly, and Velvet Revolver.

Users who click on the link are taken to a Web page containing a malicious script and a Trojan horse designed to make the victimized machine part of a major botnet used to spam out more malware and junk e-mail, or even launch denial-of-service attacks.

"Earlier this week, hackers were pretending that their e-mails pointed to a YouTube video, before that they posed as e-cards or breaking news stories," said Graham Cluley, senior technology consultant for Sophos, in a written statement. "What's clear is that they will keep on adopting new disguises to try and infect the Windows computers of innocent Internet surfers. "Some may find the prospect of viewing the next Beyonce video irresistible. This is less of a technological problem, and more of a human problem. It may sound like a broken record because we say it so often, but people need to stop clicking on links in unsolicited e-mails or risk a computer virus infection."

Dirk Kollberg, another researcher at McAfee's Avert Labs, noted in a blog that the Storm worm authors gave their attacks a rest last week.

Kollberg reported that at 9:45 p.m. GMT last Thursday, the Storm botnet simply stopped sending out e-mails. No e-cards. No fake news alerts. Nothing. The researcher found the quiet so strange that he contacted his counterparts at MessageLabs, who reportedly told him they were seeing the same thing.

It didn't last long, though. Thirteen hours later, at 10:45 a.m. GMT, it started up again.

Kollberg did note in his blog entry that while the botnet wasn't sending out e-mails, it was connecting to the peer-to-peer network and transferring data.