We are not a virus removal forum--just a forum for ClamWin users. However...Google is your friend! Do a search for helpful information on almost any topic at Google. A search for your virus turned up several possible sources. You have to be careful, however, because some of them can be geared to make money and not really to helping you. Let me suggest this one that I trust:
http://www.bleepingcomputer.com/forums/t/632174/adfarm-mediaplexcom-show-up-when-i-visit-paypal/#entry4122647 on the web. I like Bleeping Computer--it has good information. Follow their advice.
The virus appears to be adware related, so it's probably not too bad.
Let me suggest that you lose McAfee! Here a few good free AVs (in no particular order): Windows Defender, Fortinet Forticlient, Sophos Home, AVG, or Avast. If you want to pay for one: let me suggest (in no particular order): Emsisoft, Eset, Avira, Kaspersky, or Bitdefender.
Good luck!
Regards,