What browser are you using? The only details about this I can find is that it may have installed as an add-on. If it is listed in your browser add-ons simply remove it. It doesn't appear to be malware hence not being detected by McAfee, but looks to be more nuisance-ware than anything else.
Message was edited by: Ex_Brit on 26/12/11 1:01:20 EST PM
This link from mcAfee will assist you in resolving your issue. Please be sure to run the Stinger scan which is mentioned and let us know if this resolves the problem. Required Reading - Home User Assistance Malware Troubleshooting
When you have finished and if the issue is still there, try this free program and let it clean everything it finds and rebbot the computer. http://www.malwarebytes.org/products/malwarebytes_free
Glad you are OK now.