From Adblock Plus:
Adblock Plus for Internet Explorer is an addon for your Internet Explorerthat blocks advertisements and annoying banners coming on Web pages. It blocks video ads on YouTube, Facebook ads, flashy banners, pop-ups, and pop-unders. With Adblock Plus for Internet Explorer you can easily disable all tracking, and browse the web truly anonymously. Adblock Plus can be configured to block domains known to spread malware, protecting your computer against viruses, Trojan horses, worms, spy- and adware.