New worm transcodes MP3s to try to infect PCs

A new variety of malicious software could pose a danger to those who download music files on peer-to-peer networks.
  • (IDG News Service)
  • — 21 July, 2008 08:20

A new kind of malicious software could pose a danger to Windows users who download music files on peer-to-peer networks.

The new malware inserts links to dangerous Web pages within ASF (Advanced Systems Format) media files.

"The possibility of this has been known for a little while but this is the first time we've seen it done," said David Emm, senior technology consultant for security vendor Kaspersky Lab.

Advanced Systems Format is a Microsoft-defined container format for audio and video streams that can also hold arbitrary content such as images or links to Web resources.

If a user plays an infected music file, it will launch Internet Explorer and load a malicious Web page which asks the user to download a codec, a well-known trick to get someone to download malware.

The actual download is not a codec but a Trojan horse, which installs a proxy program on the PC, Emm said. The proxy program allows hackers to route other traffic through the compromised PC, helping the hacker essentially cover their tracks for other malicious activity, Emm said.

The malware has worm-like qualities. Once on a PC, it looks for MP3 or MP2 audio files, transcodes them to Microsoft's Windows Media Audio format, wraps them in an ASF container and adds links to further copies of the malware, in the guise of a codec, according to another security analyst, Secure Computing.

The ".mp3" extension of the files is not modified, however, so victims may not immediately notice the change, according to Kaspersky Lab.

Most savvy PC users are aware of the codec ruse, but the style of attack is still effective since many media players do need to receive updated codecs occasionally in order to play files.

"Users downloading from P2P networks need to exercise caution anyway, but should also be sensitive to pop-ups appearing upon playing a downloaded video or audio stream," Secure Computing said.

Users on a digital audio enthusiast site differed over the danger level of the malware.

"I never allow programs to choose which codecs I use to play back media," wrote JXL on the Hydrogen Audio forum. "I research it and get the codec bundles off of sites I know to be trustworthy and even then I still scan them and check to make sure they are what they are. I honestly don't feel that this malware has a very good chance of spreading fast."

But most users will probably think the prompt to download a codec is just routine business, wrote a user by the nickname of Citay on the same forum.

"I think that outside a minority of users who really know about all the dangers implied with Internet use, the vast majority of people have no idea that such a codec download could lead to a Trojan infection," Citay wrote.

Trend Micro calls the malware "Troj_Medpinch.a," Secure Computing named it " "Trojan.ASF.Hijacker.gen" and Kaspersky calls it "Worm.Win32.GetCodec.a."

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

Jeremy Kirk

IDG News Service
Comments are now closed.

Latest News Articles

Most Popular Articles

Follow Us

GGG Evaluation Team

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.

Steph Mundell

LIFEBOOK UH574

The Fujitsu LifeBook UH574 allowed for great mobility without being obnoxiously heavy or clunky. Its twelve hours of battery life did not disappoint.

Andrew Mitsi

STYLISTIC Q702

The screen was particularly good. It is bright and visible from most angles, however heat is an issue, particularly around the Windows button on the front, and on the back where the battery housing is located.

Simon Harriott

STYLISTIC Q702

My first impression after unboxing the Q702 is that it is a nice looking unit. Styling is somewhat minimalist but very effective. The tablet part, once detached, has a nice weight, and no buttons or switches are located in awkward or intrusive positions.

Resources

Best Deals on GoodGearGuide

Compare & Save

Deals powered by WhistleOut
Use WhistleOut's technology to compare:
Mobile phone plans & deals
Mobile phone models
Mobile phone carriers
Broadband plans & deals
Broadband providers
Deals powered by WhistleOut
WhistleOut

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?