I think, this has nothing to do with McAfee Software. You may get a bad browser plag-ins installed on your system. Try to go to browser tools->Mange Add Ons manu to disable suspitious plug-ins and extensions.
Can you please take me through step by step.
This is caused by browsers either being behind in updates, bad add-ons or non-default settings, the cure being to reset browsers to default settings, or even switch browsers. Check this out, it's for blank McAfee interface but as McAfee uses IE for display purpose, it might help: https://community.mcafee.com/docs/DOC-3000
Let me know what kind of browser you are running, IE, firefox or Chrome?
Moved to General Discussion as this has nothing to do with Network.
I presume its a Windows 7 PC. Try the below steps and post back the results.
Goto java.com and install the latest Java Version which will be Java 7 Update 51. Close Browsers to continue Java Installation. Make sure you uncheck the Ask Toolbar installation.
Open Run dialogue (Win + R) > Type appwiz.cpl > OK You will see the list of Installed Programs.
Check if you have the below programs listed.
Java 7 Update 51
Microsoft Visual C++ Redidtributable 2010 (2005 , 2008 might also be present)
Post back if you don't have the above..!