NetSky.B Worm Gains More Traction

By Matthew Hicks  |  Posted 2004-02-19 Print this article Print

The mass-mailing e-mail worm, a more virulent variant of an earlier worm, is considered a medium-to-high threat as it trolls folders for e-mail targets.

A new mass-mailing worm, called NetSky.B, is spreading rapidly after beginning to make the rounds of e-mail inboxes on Tuesday. NetSky.B is a variant of the NetSky.A worm identified earlier in the week, but is posing a greater risk of spreading and infecting machines, security vendors warned Wednesday. Symantec Corp. rated NetSky.B a Category 4 threat, its second-highest level, while Network Associates Inc. and F-Secure Corp. rated it as a medium threat. NetSky.B is distributed through e-mails as a ZIP archive or an executable attachment. Once opened, the worm runs a file and then displays a fake error message that reads, "The file could not be opened!"
Once infecting a machine, the worm searches for e-mail addresses and scans hard drives and mapped drives, including drives C through Z, for folder names that contain the words "share" or "sharing." It then copies itself to those folders and, when an Internet connection is present, starts spreading through ZIP archives and other attachments to e-mail.
Symantec reports more than 1,000 infections and more than 10 sites. While the worm does not appear to be malicious by deleting files or crashing systems, it can degrade performance, security vendors report. Network Associates in its security alert reports that NetSky.B attempts to deactivate the MyDoom.A and MyDoom.B viruses, which earlier this month overloaded e-mail inboxes worldwide and included payloads to trigger DoS (denial-of-service) attacks against the Web sites of the SCO Group Inc. and Microsoft Corp. NetSky.B affects systems running Microsoft Windows 95 and higher. It does not affect systems running earlier versions of Windows or running Linux, Mac OS X or Unix, according to Symantec. Check out eWEEK.coms Security Center at for security news, views and analysis.
Matthew Hicks As an online reporter for, Matt Hicks covers the fast-changing developments in Internet technologies. His coverage includes the growing field of Web conferencing software and services. With eight years as a business and technology journalist, Matt has gained insight into the market strategies of IT vendors as well as the needs of enterprise IT managers. He joined Ziff Davis in 1999 as a staff writer for the former Strategies section of eWEEK, where he wrote in-depth features about corporate strategies for e-business and enterprise software. In 2002, he moved to the News department at the magazine as a senior writer specializing in coverage of database software and enterprise networking. Later that year Matt started a yearlong fellowship in Washington, DC, after being awarded an American Political Science Association Congressional Fellowship for Journalist. As a fellow, he spent nine months working on policy issues, including technology policy, in for a Member of the U.S. House of Representatives. He rejoined Ziff Davis in August 2003 as a reporter dedicated to online coverage for Along with Web conferencing, he follows search engines, Web browsers, speech technology and the Internet domain-naming system.

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