The sophisticated 2006 backdoor trojan dubbed Rustock will be modeled by attackers in 2007 and beyond, security experts warn. The trojan uses advnaced rootkit technologies to avoid detection and bypass security software.

 Rustok buries itself into systems, makes changes to the registry system to hide its activities and spews out image spam from hijacked computers. The polymorphic malware can be extremely difficult to find once it is embedded on a system.