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.
Trojan - A Trojan software is any software on a user's computer that the user is not aware or intentionally installed. Most Trojan software is designed to perform some sort of actions that could jeopardize the user's security or privacy.