Storm Worm sent 15 million pump-and-dump e-mails last month

Storm worm sent out 15 million MP3 pump-and-dump spams in October.

The Storm Worm botnet network may be shrinking in size, but it has managed to send out 15 million of those annoying audio spam messages in October, according to antispam vendor, MessageLabs.

It's hard to believe that the Storm messages were effective. Recipients had to first click on an attachment -- usually given a misleading name like beatles.mp3 or Britney.mp3 -- to hear the stock pitch, which featured a warbly robotic woman advising people to invest in online car seller, Exit Only.

This kind of scam, called "pump-and-dump", tries to nudge up the price of penny stocks by a cent or two, giving the spammers a way to make a quick buck by selling the stock before it crashes. Spammers have been delivering their messages in different formats, including .pdf and Excel files, over the past few years as part of a cat-and-mouse game with spam blockers. This latest move to MP3 spam is the latest development in this battle, observers say.

Spam watchers say that pump-and-dump schemes are the hottest and most lucrative area for spammers today.

The spam run began on Oct. 17, and lasted about 36 hours, using infected computers in the Storm Worm network to send out the mails, MessageLabs said in a statement. The spam sounded strange and warbly because the voice in the message was "synthesized using a very low compression rate of 16K Hz to keep the overall file size small, at around 50 KB, to avoid detection," the company said.

Storm is thought to have landed on as many as 15 million PCs over the past year, but recently its network of infected PCs has been shrinking. University of California, San Diego, researchers recently pegged it at about 160,000 computers, only 20,000 of which are accessible at any one time.

Exit Only said it was not involved in sending the spam. Its stock was trading around US$0.41 on October 18, the day after the Storm spam started. On Tuesday it closed at US$0.20.

Join the PC World newsletter!

Error: Please check your email address.

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Robert McMillan

IDG News Service
Show Comments

Essentials

Lexar® JumpDrive® S57 USB 3.0 flash drive

Learn more >

Microsoft L5V-00027 Sculpt Ergonomic Keyboard Desktop

Learn more >

Mobile

Lexar® JumpDrive® S45 USB 3.0 flash drive 

Learn more >

Exec

Lexar® Professional 1800x microSDHC™/microSDXC™ UHS-II cards 

Learn more >

Audio-Technica ATH-ANC70 Noise Cancelling Headphones

Learn more >

Lexar® JumpDrive® C20c USB Type-C flash drive 

Learn more >

HD Pan/Tilt Wi-Fi Camera with Night Vision NC450

Learn more >

Budget

Back To Business Guide

Click for more ›

Most Popular Reviews

Latest News Articles

Resources

PCW Evaluation Team

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Kathy Cassidy

STYLISTIC Q702

First impression on unpacking the Q702 test unit was the solid feel and clean, minimalist styling.

Anthony Grifoni

STYLISTIC Q572

For work use, Microsoft Word and Excel programs pre-installed on the device are adequate for preparing short documents.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?