Trojan Horse With All Its Specifics

How does the Trojan Horse attack a processor or a computer in general?How does it enter the computer or any other device? Does it spread or no?

How does the Trojan Horse attack a processor or a computer in general?How does it enter the computer or any other device? Does it spread or no?
Hi
The Trojan Horse, at first, appears as a harmless program which we find useful, but it will perform damage once we have installed it or run it on our computer. They appear as a legal software or file from a renowned source and hence, people get tricked into installing/ running them. They never self-replicate, and they do not reproduce by infecting other files.
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A Trojan horse is a malicious program or a harmful code that is confined inside an actually safe program or data in such a way that it can gain control and perform its selected damage like for example damaging the file system of a hard drive. It can be widely distributed as part of a computer virus.
It is a malicious program that pretends to be useful or interesting to be able to convince the user to install it. The term Trojan horse comes from the Greek mythology about the Trojan War as mentioned in the Odyssey by Homer and told in the Aeneid by Virgil. The legend says the citizens of Troy were presented with a large wooden horse by the Greeks.
They don’t know that the Greeks hid their warriors inside the wooden horse. When the night comes, the warriors appeared from the wooden horse and overran the city. Trojans are generally distributed by some kind of social engineering like for example tricking a user to execute an email attachment disguised as unsuspicious and sometimes by drive-by download.
Though their payload can be anything, lots of modern forms of Trojans act as backdoors which contacts a controller and then gives unauthorized access to the affected machine.