Well, it is not exactly a virus, but babylon plugin can impose itself on your browser in form of search toolbars or default search setting. It has happened to me more than once now, so sharing some quick steps of getting rid of it here. Please note that at times this app/ toolbar will be stored as any other name, so look out for anything suspicious and out of place.
1. Remove the app: Check if a program is shown under add/ remove program (go to control panel-> uninstall program) with name babylon. Remove it.
2. Remove toolbar: Check if toolbar exists under browser toolbars, and remove it.
Firefox: Go to Add Ons->look for babylon
IE: Go to Manage Add Ons->Toolbars and extensions->look for babylon
3. Remove as default search engine: For IE Manage Add Ons-> Search providers->babylon (in my case it was named just default)