Don't know for sure, but here's a couple things you can do (remember, there's alternative programs to any of these).
1) For ads, malware, spam, etc., try using Lavasoft's Ad-Aware. It does a scan, and tells you all the tracking cookies, etc. It's free for the basic version.
2) for Virus scanning, there's Avast, which is free for home use (but not for commercial purposes). Updates constantly, which means they're trying to stay on top of things.
Do a scan, and see what it comes up with. Quarantine, then remove.
You can also flush out your cookies (though it will also flush out passwords if you're not careful), and clean out your history file, which can be done (in Mozilla Firefox, at least) with Tools, Clear Private Info. Internet Exploder should have something similar...