I'm just guessing, but it doesn't sound like something RealPlayer would do. I've never had that happen. It's a 'redirect', and may not even be a real Real site.

Until more knowledgable people than myself show up, you can't go wrong if you:
1) Make sure your anti-virus & anti-spyware programs have been updated recently, like today, and
2) Run a full system scan

Don't believe you can't get infected. I have an anti-virus program that updates daily, Zone Alarm, SpyBot Search & Destroy, Spyware Blaster and CWShredder. When I did a full system scan, I found 2 files infected with win32:Caca. I don't think it was actually able to DO anything, but it was there, and it might have been why I've had to do a complete system restore twice and almost a third time. That wacky behavior made me do the full scan, and once the trojans were gone, the problem (system wouldn't boot up all the way) stopped.

So try the update and check for bad things first.