Doing a Google search seems to bring up a couple of similar questions. It appears to be something called Engine X. It MAY NOT be a virus - general advice seems to be clearing your Internet history and restarting your Browser.
Probably wouldn't hurt to check your Security settings are up-to-date and do a scan, just to be sure. It could be something on a certain site that you might not be able to do anything about. Someone else with more knowledge might be able to shed more light on the subject.



