This is a real virus! 

Get this E-mail message sent around to your contacts ASAP. PLEASE FORWARD THIS WARNING AMONG FRIENDS, FAMILY AND CONTACTS! You should be alert during the next few days. Do not open any message with an attachment entitled 'Invitation' OR ONE CALLED 'POSTCARD,' regardless of who sent it to you. It is a virus which opens an Olympic Torch OR A POSTCARD IMAGE, which 'burns' the whole hard disc C of your computer. This virus will be received from someone who has your e-mail address in his/her contact list. This is the reason why you need to send this e-mail to all your contacts. It is better to receive this message 25 times than to receive the virus and open it.

If you receive a mail called 'Invitation' even though sent to you by a friend, do not open it. Shut down your computer immediately.