Washington A new virus-like attack struck large companies Tuesday, and its rapid spread threatened to slow down the Internet. Atty. Gen. John Ashcroft warned the computer outbreak could become worse than the "Code Red" worm earlier this summer.
The malicious software program, known as W32-Nimda, is complex and designed to spread to people who open infected e-mail or visit an infected Web site. The program generated more traffic on the Web, slowing down many users.
The worm can spread in many different ways. It can infect Web sites running Microsoft's Internet Information Services software. Once a Web site is infected, any Web user accessing it can get the worm.
Once one computer on a company network is infected, it can also travel across the network to attack others.
Finally, it can send itself through an e-mail attachment. The sender address is faked, and may be a well-known address. Researchers said they weren't sure how the address was generated. The attachment may be named "README.EXE."