Zlob trojan
The Zlob Trojan, identified by some antiviruses as Trojan.Zlob, is a Trojan horse which masquerades as a required video codec in the form of ActiveX. It was first detected in late 2005, but only started gaining attention in mid-2006. Once installed, it displays popup ads which appear similar to real Microsoft Windows warning popups, informing the user that their computer is infected with spyware.