Virus-like program that spreads automatically to other computers by sending itself out by email or by any other means. A program that propagates itself by attacking other machines and copying itself to the affected machine.
Worms have self-replicating code that travels from machine to machine by various means. A worms first objective is merely propagation. Worms can be destructive depending on what payload they have been given. Worms may replace files, but do not insert themselves into files.
Newer versions of this worm can disable vital Windows diagnostic tools such as Task Manager and the Registry Editor.
Infection messages sent by infected Yahoo IM user.
The site that hijacks the IE homepage when the infection is run.