A native of ancient Troy.

Of or relating to the ancient city of Troy or its inhabitants.

A form of malware that often can do considerable damage to a system or network.
Trojans are distinguished from other malware such as
viruses and worms in two ways:
. They generally are stealthy in operation and often masquerade as legitimate programs, while viruses and worms usually have a more obvious effect such as corrupting files or causing a system to crash.
. They usually don’t replicate like viruses and worms do.
The terms Trojan and Trojan horse originally meant malicious code hidden inside a legitimate, useful program, much as the original Trojan horse hid enemy soldiers within an innocent-looking sculpture. If a Trojan attaches itself to some legitimate program to modify that program’s behavior, it is sometimes called a Trojan virus. Most Trojans nowadays are self-sufficient executable (*.exe) files that malicious hackers insert in compromised systems to gain control over the system or steal users’ data. Trojans can also infect systems when users download applications such as games from untrusted sources on the Internet. Such games may have Trojan code embedded in them that can give a cracker a foothold in a system and threaten the integrity of data.