American antivirus software company Central Command has discovered what it believes to be the first HTML virus.
The virus, called HTML.Internal, affects only Microsoft's Internet Explorer browser. Whenever a user visits a Web page infected with the virus, a Visual Basic script is activated that can add strings of text to any HTML document in the user's PC, said Keith Peer, president of Central Command.
Users who have activated Microsoft's security mechanism will be warned that they are about to run an unsigned document. But users who aren't using the Microsoft security system will activate the virus, Peer said.
A Microsoft spokeswoman said the company is investigating the virus but hasn't yet determined whether it is a security issue.
Central Command's antiviral software has been updated to detect the HTML.Internal virus.