A rapidly spreading computer worm shut down e-mail systems at several large corporations yesterday and was causing problems for computer users connected to the Internet, security experts said.
Known as "MyDoom," it is the fastest-spreading e-mail worm ever, according to Network Associates Inc., the Santa Clara, Calif.-based maker of McAfee security software. The company classified it as a "high alert," its most severe rating. The experts did not identify the affected companies.
MyDoom already is causing serious disruptions for businesses and home computer users, said Steven Sundermeier, product manager for Central Command Inc., an anti-virus company in Medina, Ohio. Sundermeier said the worm is spreading fastest in the United States and Europe.
The worm is contained in an e-mail message that looks as if it were garbled during its journey to the recipient's in-box. The body text urges recipients to click on the attached file if the contents of the message are damaged or unreadable.
If a user clicks on the file and his computer is infected, it is programmed to send large amounts of data to attack the Web site of the SCO Group Inc., a Lindon, Utah-based company that, in effect, asserts ownership over portions of the widely used Linux open-source operating system. SCO is pursuing legal action against International Business Machines Corp. and other companies, asserting that Linux includes portions of the Unix operating system to which it claims copyright ownership.
The open-source community disputes SCO's claims on Linux.
The more immediate problem for computers infected with the worm is that they will automatically allow the worm's authors to connect remotely and upload malicious files, such as software to forward spam e-mails. The worm also creates a mass-mailing of itself, which is expected to clog many corporate e-mail servers or slow down Internet traffic, according to Symantec Corp., a Cupertino, Calif.-based anti-virus software developer.