A Trojan horse (also known as a Trojan) is one of several kinds of malware you might find on your computer after a successful virus attack. Trojans are a particularly sneaky kind of malware because they look harmless or even beneficial and trick you into installing them on your system. Trojans fall into the category of “social engineering” attacks because they trick people. Trojans are typically used by cybercriminals for online fraud and theft. Antivirus software and anti-malware help protect you by keeping Trojans off your computer system by recognizing that they’re actually malware. But don’t rely on antivirus software alone. You should always only download and install software when you know what it is and who it’s from.
Why do we call this kind of malware a “Trojan horse?” Because in Greek mythology, the Greeks won the Trojan War by building a hollow horse, filling it with soldiers and leaving it for the Trojans, supposedly as a gift. A Trojan priest was suspicious of the “gift” and said to “beware of Greeks bearing gifts” but the Trojans ignored him and brought the horse through the gates into the city. Later, when the Trojans were asleep the Greek soldiers jumped out, captured the city and burned it to the ground.
And so the “Trojan horse” came about.
What does this have to do with you? In the world of viruses and malware, cybercriminals create viruses or malware that look harmless or useful but actually aren’t. Just like the Trojan horse, it’s really hiding something that’s meant to attack you once it’s inside your system. For example, a Trojan horse might look like an Android app that you want (like the hot new game “Angry Birds Space”) but in fact, it’s malware waiting to get a hold of personal information on your system.
Antivirus and security software helps protects you by looking inside the “horse” to see what’s really there. And if your antivirus solution sees that there’s a virus or malware inside, it can protect you by blocking it from your system.
Trojan horses have been around on PCs for a while. But as online activity grows and expands, criminals are making Trojan horses for all sorts of devices you might use to connect to the Internet: PCs, Macs, smartphones and tablets. Don’t be fooled into thinking that only some kinds of machines like PCs are targets; any device that connects to the Internet is a target. A reputable antivirus product will help protect your devices against Trojan horses. So the best thing you can do is to run up-to-date antivirus software products (free or not) on all your devices.
Unfortunately, because Trojan horses make lots of money for their creators, they’re here to stay. But with a good antivirus, anti-malware security software, you can be smarter than the Trojans and keep the criminals’ “gifts” off your system.