Besides Firefox's own settings I add AdBlock+ and Web Of Trust.
HOWEVER, redirection done at the web site should not be blocked. There is malware that McAfee does not block or remove (long story about court cases where the adware folk demanded the antivirus companies keep their hands off their adware.)
If Adblock and WOT doesn't help, try scanning with tools (free) noted by Grif at
http://forums.cnet.com/7726-6122_102-5509131.html?tag=posts;msg5509131
Bob
New Dell desktop, Win 8.1, Mozilla Firefox , free McAfee virus protection.
How can I eliminate pop ups and redirects?

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