Web bugs 'stalk' Microsoft users

Concerns are likely to be raised among Microsoft users by a report that states Word, Excel and PowerPoint documents can be tracked via the web.

According to an advisory statement issued by the Privacy Foundation this week, any document containing an image file located on a remote web server can be marked invisibly with a 'web bug' within the most widely used Microsoft applications. When the file is opened the bug sends back a message to the host containing the IP address of the reader's computer.

The bug can also track the IP address of any reader the document may be forwarded to.

Richard Smith, CTO of the Privacy Foundation, said he was not aware of web bugs being used yet, but the possibility of being monitored should be of concern to businesses and individuals.

The group presented its findings to Microsoft last month. The software giant acknowledge the potential of web bugs to track documents but said it had not yet heard of the technology being used this way.