Need Help please.

Hello,

On the 20th of June a new Icon showed up on my desk top, after talking to a friend he asked email him a copy of the file. He came back with a copy of my outlook express address book, it looks like all my contacts are located in this file but he does not know what it means. The icon is a window with a sideways S located under it. I have run virus scan from McAfee and have updated my machine from Microsoft as well as McAfee but scans are not showing anything.

Does anyone know what this is? If you do how can I remove this?

Thank you fo your help.