According to a non-profit org study (SANS):

As more Windows users agreed to receive security upgrades automatically, hackers looked to take advantage of other software programs that might not be patched as frequently … software by Oracle Corp. and Computer Associates International Inc. also made the list, along with media players like Apple's  iTunes, RealNetworks Inc.'s  RealPlayer, and Nullsoft's Winamp. Antivirus products from Symantec Corp. F-Secure, TrendMicro and McAfee Inc. proved vulnerable as well, a prospect Paller found particularly discouraging.

http://money.cnn.com/2005/05/02/technology/microsoft.reut/index.htm