Greetings from your friendly virus, again

Computer users are at risk of a breach of privacy caused by fake greetings card emails that trigger a mass mailing from personal online address books.

The greetings card is designed to give the email sender access to private data before sending out a copy of the card to every name in the computer user's address book.

The virus has only just been uncovered in the US but has already been seen in this country and is similar to other, similar viruses appearing increasingly regularly on the web.

Computer users are lured to an electronic greetings website via the fake card, which usually appears to have been sent by a regular correspondent. Once on that site users are invited to access their greetings card by installing additional software.

This software interrogates the user's electronic address book and distributes copies of the card to all names saved there.

Computer security firms are concerned about the implications of installing such software and the intrusion into private data brought about by the virus.

Jack Clark from McAfee, a computer security company, said: "It is a threat which people need to look out for. Too many will click the "yes" box and install unwanted software because they are in a hurry to access their card. It is critical that we are more careful and read all licence agreements thoroughly."

The card was created by a Panama firm with a marketing background. Although not technically a virus, it is so widespread that security firms are adding detection of the software to anti-virus packages.