Please uninstall the McAfee product by following the instructions on whichever of the pages linked below is applicable:
How to install or uninstall McAfee Internet Security for Mac
How to manually remove VirusScan for Mac 8.6.x using a removal script
How to uninstall and reinstall McAfee Agent 4.x on Macintosh computers
Note that if you have already tried to uninstall the software, you may have to reinstall it in order to finish the job. If you have a different version of the product, the procedure may be different.
Back up all data before making any changes. Never install any "anti-virus" or "anti-malware" product again.