I used to work as a marketing associate for an IT firm up until 2 weeks ago. There seems to be a lot of Trojan Viruses going around that many of the popular AV programs, including Symantec, cannot detect. The techs used a free software called Mallwarebytes that detects almost anything and will repair or quarrantine the virus. It's at http://www.malwarebytes.com

Good Luck

Pat