Cloud, I'm nowhere near an expert on infections, but perhaps I can help. If this problem is on Windows, I would download Panda Cloud AV. It's completely free and has very good detection and cleanup. Install it and see what it says. After that is when I would go on and try MBAM (Malwarebytes Antimalware). Now, please be careful when searching for them on Google. In the case of Panda, its website is listed right at the top of the results. Sometimes though Google will put an ad up there so watch where you click. Chances are you have some silly little browser toolbar/addon that got installed with another program that is causing this spam nightmare. They are annoying, but usually not very dangerous. They are also usually easily removed.
Now, to avoid things like this in the future, there are a few things you can do.
1. When you download programs, try to download them directly from the vendor website. Anymore these days they send you to a third-party like Sourceforge or CNET Download regardless, but try. If it does have to come from somewhere like CNET Download, watch for any check-boxes during the opening of the file or installation of the program. You need to do this regardless of where you download a file because these days vendors often bundle other products and services with their program
2. Use "Click-to-Play" for Flash in Chrome if you are still using that browser. You can do that by going to Settings, clicking Advanced Settings at the bottom, then under Privacy you want to click Content Settings and choose "Let me choose when to run plugin content". This will avoid possibly malicious Flash ads that are an all too common entry for malware infections.
3. Run a program like Sandboxie, that is capable of discarding any unwanted changes to the browser or computer during a session.
Another reason I think Panda is a good idea, is because it has web scanning capability that can keep bad websites at bay. Be aware that Panda URL scanning by default comes with a toolbar, but it is rather harmless and easily removed through the control panel. The nice thing is, removing the toolbar does not remove URL scanning
I hope I've helped in any small way.