It is fun how terms get their name. Often they borrow from other venues and genres. So is with the word Trojan in cyber language.
The term [Trojan horse} is derived from the Ancient Greek story of the large wooden horse used to trick defenders of Troy into taking warriors concealed in the horse into their city in ancient Anatolia. https://en.wikipedia.org/wiki/Trojan_horse_(computing)
That is how the word got its meaning. What is it and what can Trojans do to your computer, laptop, tablet or phone? How are they different than viruses?
It [a Trojan] is a harmful piece of software that looks legitimate. Users are typically tricked into loading and executing it on their systems. After it is activated [which can happen automatically when downloaded], it can achieve any number of attacks on the host [the host can be your computer, tablet, laptop or phone], from
- Irritating the user by popping up windows or changing desktops to damaging the host by deleting files, stealing data, or activating and spreading other malware, such as viruses.
- Creating back doors to give malicious users access to the system [i.e. files, documents, emails, passwords].
Unlike viruses and worms, Trojans do not reproduce by infecting other files nor do they self-replicate. Trojans must spread through user interaction such as opening an e-mail attachment or downloading and running a file from the Internet.