McAfee's sponsored ad links on Google apparently claims that BitDefender is a virus which users need to clean up. BitDefender is, of course, a Romanian antivirus company, who are none too pleased about the ad. They see it as a direct attack on their brand name - a deliberate attempt to damage the company.
McAfee have denied placing the ad. They claim to have no idea as to the source of the advertisements. It is possible that the ad was placed by a McAfee affiliated company.