A Trojan horse, or Trojan, is a type of malicious code or software that looks legitimate but can take control of your computer. A Trojan is designed to damage, disrupt, steal, or in general inflict some other harmful action on your data or network.

A Trojan seeks to deceive you into loading and executing the malware on your device by acting to be a desired game or the song you like so much. You might also for example think you’ve received an email from someone you know and click on what looks like a legitimate attachment. But you’ve been fooled. The email is from a cybercriminal, and the file you clicked on — and downloaded and opened — has gone on to install malware on your device.Once installed, a Trojan can perform the action it was designed for.

Trojans usually are employed by cyber-thieves and hackers trying to gain access to users' systems. They can enable cyber-criminals to spy on you, steal your sensitive data, and gain backdoor access to your system.