Its been going around the web. High numbers of the same at work.
If you force close the IE process in task manager, re launch IE (or Chrome) it should resolve the issue. If you are using IE be sure to clear the IE cache.
Note: Do not restore pages if your browser asks you to.
Also: it may take several attempts to end the process, the ad will attempt to re-open itself until the proper instance of the IE or Chrome process is ended.
[member="Ajira Cardei"] | [member="Catalys Maijora"]