Why did my facebook account send a message to everybody on my list from me? Virus?

[................................]

It sent the same message to my contacts saying to visit a website and find out who their crush is. I dont download anything on facebook and i have about 2 applications. I dont understand how I can have got a virus and other people didnt. Can somebody explain please.

[Kenn]

I heard there was this virus one time I think it was called love bug now the basis of this if you open an e-mail with a attachment it could either be that virus now one of your Friends must have gotten that virus and now the effect everyone in the address book will also receive that virus

[Darren0901]

Download, install and run CCleaner to clean up old temp files.
http://www.ccleaner.com [Free]

Restart your PC in safe mode with networking
http://www.pchell.com/support/safemode.shtml

Download, install and run a full scan with Malwarebytes
http://www.malwarebytes.org

Run a full scan with Micro Trend House Call
http://housecall.trendmicro.com/

After the scans, restart the PC and update your anti-virus, remember to only have one anti-virus installed on your PC
http://www.avast.com/eng/download-avast-home.html [Free, if you do not have one]