Homeland security offers alerts warning of e-mail viruses.

In January, the biggest computer worm thus far--dubbed "MyDoom"--hit e-mail servers hard: 1 in 12 e-mail accounts was affected. The worm, which appeared as an innocuous error message, clogged global e-mail traffic worldwide and even forced some companies to shut down their mail servers in an attempt to stop its spread.

The U.S. government wants to make sure that when the next computer virus is let loose to wreak havoc, computer users are ready. In an attempt to increase Internet security, the government is now offering Americans free cyber alert e-mails and computer advice from the Homeland Security Department.

Anyone who signs up with the new National Cyber Alert System (www.uscert.gov) will receive e-mails about major virus outbreaks and other Internet attacks as they occur, along with detailed instructions to help computer users protect themselves.

The goal of improving the overall security of the Internet has been frustrated by increasingly complex software that can be difficult to secure and by hackers launching sophisticated new attacks. The announcement comes 11 months after such an Internet warning system was described in the National Strategy to Secure Cyberspace, a series of proposals endorsed by the Bush administration and the technology industry to improve online security. The alerts will function independently from the Homeland Security Department's color-coded system that reflects the national threat level.

The new alert system sets up potential conflicts with leading software companies, including Microsoft Corp., which aggressively discourage any public disclosures about new security flaws in their products until engineers can study them and offer remedial software patches for their customers. Researchers who discover new vulnerabilities commonly work closely with these companies by agreeing not to reveal details about their work until a software patch is available. But some researchers have complained that companies take too long to verify their discoveries or deliberately seek to minimize their efforts for marketing purposes.

Amit Yoran, the administration's cyber security chief, said the government will aggressively warn consumers about vulnerabilities, in some cases revealing threats "above and beyond what specific commercial vendors may not wish to disclose. If the disclosure of certain information is deemed in the public interest, we'll move forward," he said.