Trojan (Trojan Horse)

A Trojan, or Trojan horse, is a type of malicious software that disguises itself as legitimate software. Named after the ancient Greek story of the deceptive wooden horse that led to the fall of the city of Troy, Trojans similarly trick users into loading and executing them on their systems. Unlike viruses, Trojans do not replicate themselves but they can be just as destructive.

Trojans are typically spread by some form of social engineering, where users are duped into running an email attachment or downloading and installing software that appears legitimate but actually has a hidden malicious agenda. Once installed, a Trojan can perform a range of harmful activities on the backend, from simple disruptive tasks like changing desktop backgrounds or adding icons, to more dangerous actions such as stealing data or creating backdoors in the security of the infected system.

These backdoors can give cybercriminals direct access to your computer system, allowing them to send, receive, launch, and delete files, display data and reboot the computer. Trojans can also capture keystrokes and logins, and steal sensitive personal information like passwords, credit card numbers, bank information, or personal identities.

The damage caused by Trojans can vary significantly depending on what they are designed to do. Some Trojans are specifically designed to spy on the user, while others may turn the infected computer into a bot for the attacker to use in a larger network to spread more malware, or to initiate a denial of service attack against other targets.

Protecting against Trojans involves a mix of user vigilance and software solutions. Users should be wary of downloading and running unknown programs, should keep their systems updated, and use reputable antivirus software that can detect and remove any Trojan infections. Regular backups of important data can also help to minimize the damage in case an infection does occur.