Download and install Symantec AntiVirus software at:

http://www.columbia.edu/cuit/software/nav/

Once you have installed the software, use its LiveUpdate feature to obtain the latest virus definitions, then run a full system scan. It is typically more effective to run the scan in safe mode, although it takes a bit longer.

Visit the Symantec page about virus alerts:

http://securityresponse.symantec.com/