A Trojan horse virus (often known simply as a Trojan), is unlike other viruses and worms as it does not self-replicate or reproduce by infecting other files. Instead, Trojans require a user to interact with it in some way, such as downloading and running a file from the Internet, or opening an e-mail attachment.
Therefore, before a Trojan horse program can attack, it must first find a way to entice the victim to copy, download, and run it by appearing harmless. Then it spreads like wildfire throughout a user's computer system and other devices on the same network after its victim has unknowingly downloaded it.
Before aTrojan horseprogram can attack, it must first find a way to entice the victim to copy, download, and run it. It spreads like wildfire after it's victim has unknowingly downloaded it.