Trojan horse (computing)
Trojans are generally spread by some form of trickery, for example getting users to click on bad popups, Email, text,  attachments, advertisements, or fake device driver updates. A trojan may act as a "backdoor" to the computer, contacting a controller which can then have unauthorized access to the affected computer. Trojans may also access users' personal information such as banking information, passwords, or personal identity.  It can infect other devices connected to their networks.