High Risk
High risk threats typically are remotely exploitable vulnerabilities, which can lead to system compromise. Successful exploitation does not normally require any interaction. May open up communication ports, use polymorphic tactics, stealth installations, and/or anti-spy counter measures. May use a security flaw in the operating system to gain access to your computer.
Worm - A worm is program that propagates by attacking other computers and copying itself to them. Worms may replace files, but do not insert themselves into files (as viruses do).