What is a Trojan Horse?

What is a Trojan Horse?

You might be familiar with the Greek myth of the soldiers who hid in a hollow wooden statue of a horse to enter Troy. In Internet terms, a Trojan horse works in much the same way. It’s a program intended to compromise security on your computer. It does this under the guise of doing something harmless.

A Trojan horse contains malicious code that steals data and debilitates your device.

What a Trojan horse is after

Unlike a virus, a Trojan isn’t interested in replication into other files. It’s there for one purpose. That purpose could be one of many.

  • Remote access: Trojans open back doors to a system through which a hacker can add, change, delete or run files on a computer.
  • Electronic money theft: Hackers use Trojans to make bank deposits or divert electronic funds.
  • Computer crashes: Trojans can shut down a computer system to cause the blue screen of death.

Trojans can do many more bad things. They can corrupt data, or use your device to send spam or help with a denial-of-service attack. It can affect other devices connected to it. Trojans can log keystrokes, watch your screen, and download malware.

How do I know I have a Trojan horse on my device?

Trojan.Script.Iframer affected more than 58 million devices in 2012. How can you tell if a Trojan has made its way onto your system?

  • Warnings: Some devices might turn the screen blue and warn you of a spyware infection.
  • Redirects: If your browser goes to sites you haven’t entered, that’s a sign of a Trojan.
  • Unknown programs: See programs in your system tray or toolbar? That might be a Trojan.

Your device might not even turn on if you have a Trojan. Or, programs you didn’t open will run. Are pertinent files missing? These are all signs of a Trojan.

How can I avoid Trojan horses?

Kaspersky manufactures and distributes antivirus programs. It estimates Trojans and other malware inflict more than 90% of web attacks. They’re often delivered in email links, files shared, and downloads from untrusted pages. Hackers also create pages that look legitimate, but spread Trojans.

Here are tips to avoid Trojans:

  • Watch email: Hackers create email accounts and subject lines to trick users into clicking a link. It could be to see a funny video or enter personal data. Be careful what you click and share.
  • Go plain: Text, that is. Plain-text email mode will keep surprise attacks on your system should you click a link or image.
  • Install a firewall: A good firewall is essential to Trojan protection. A firewall will keep unwanted spam email and other data packets from getting to your system.

Be sure your antivirus software is installed, with automatic updates to stay ahead of hackers. Antivirus programs also have scanning capability to ensure files you open are safe. Use caution when you open files or click links sent by email. Be sure you know the source!