What is a Trojan horse? How this tricky malware works

Trojan horse definition

A Trojan or Trojan horse is a variety of malware that disguises itself as something you want in order to trick you into letting it through your defenses.

Like other types of malware, a Trojan is deployed by attackers to damage or take control of your computer. Its name comes from the method by which it infects your computer: it disguises itself as something you want in order to trick you into letting it through your defenses.