Please see http://my.opera.com/krishnan/blog/index.dml/tag/%22I%20DNT%20HATE%20MOZILLA%20BUT%20USE%20IE%20OR%20ELSE...%22

Please scan your system using an up-to-date antivirus or antimalware program or run online scan using Housecall:
http://www.trendsecure.com/portal/en-US/free_security_tools/housecall_free_scan.php

You can also try to use Flash Disinfector from http://www.techsupportforum.com/sectools/sUBs/Flash_Disinfector.exe (note: this is direct download link)
Plug-in your USB drive then run Flash Disinfector.