Spawn of Bagle and Netsky roil Internet

Serial worm outbreaks continued on Tuesday as new variants of the Bagle and Netsky e-mail worms spread on the Internet.

Since Monday, antivirus companies identified two new versions of the Bagle worm, dubbed Bagle.H and Bagle.I, and a new version of the Netsky worm, Netsky.E, just hours after five new versions of Bagle and Netsky.D, a virulent new take on that worm, were released, antivirus companies said.

The new worms versions were rated "low" threats on Tuesday by Symantec, indicating that they were spreading slowly. However, Network Associates's (NAI's) McAfee antivirus unit increased its rating of Bagle.H from a "low" to a "medium" threat on Tuesday, based on an increased number of submissions from customers and other Internet users, said Brian Mann, outbreak manager at NAI's McAfee Antivirus Emergency Response Team unit.

NAI researchers are receiving a "couple hundred" Bagle.H submissions Tuesday, which roughly correlates to hundreds of actual infections. That prompted the rating change, Mann said.

Both new versions of the Bagle worm spread in ZIP files that require passwords to open, similar to the Bagle.F and Bagle.G variants that appeared over the weekend. The virus authors provide the password to unlock the ZIP in the e-mail message containing the virus.

Hiding their creation in a password-protected file allows authors to slip the virus by gateway antivirus filters, which cannot decode the file to read the signature of the virus inside, said Mann.

Some antivirus products can spot the virus by comparing information about the ZIP file attachment to known samples of the worm, he said.

Most new versions are modifications of previous versions, with slight changes to the subject lines, message text and attachments used to lure unsuspecting recipients, he said.

Antivirus experts don't know who is to blame for the flood of new worm variants that have appeared since mid-January, when Bagle and Mydoom first surfaced. Competing groups of virus writers may be behind the releases, using worms to battle for Internet turf that is measured in compromised hosts, Mann said.

Earlier versions of the Netsky worm removed copies of the Mydoom virus, which may be evidence of a kind of one-upmanship between virus authors, he said.

While the Bagle worm continued to throw off new variants, Netsky.D continued to assault e-mail in-boxes with virus-generated e-mail messages.

Symantec updated Netsky.D to a "severe" threat Monday, citing an "increased rate of submissions."

NAI researchers saw a decrease in the volume of Netsky.D mail on Tuesday, but still rate it a "medium" threat and expect it to "be around for a while," Mann said.

Researchers are also looking at the security risks posed by the viruses, many of which open communications ports on infected systems that can be used to upload malicious software or remotely control the infected systems, he said.

Join the newsletter!


Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Paul Roberts

IDG News Service
Show Comments

Brand Post

Most Popular Reviews

Latest Articles


PCW Evaluation Team

Luke Hill


I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?