Security company Symantec is warning Internet users of <A HREF="http://news.zdnet.com/2100-1009_22-5400982.html?tag=zdnn.alert">a Trojan horse that removes adware</A> but alters the settings in computers. While Downloader.Lunii eliminates a variety of adware programs, often known as spyware, the Trojan also tries to maliciously change the security settings of Windows PCs and then downloads files from unknown Web sites.