subject: Trojan Computer Viruses - A Brief History of a Modern Computer Plague [print this page] Trojan Computer Viruses - A Brief History of a Modern Computer Plague
During the famous siege of Troy, the Greeks built a large wooden horse inside which a large number of Greek soldiers hid. The large horse was placed outside of Troy as an offering of peace. The Trojans brought the horse into the city and later as the Trojans slept the Greeks crept out and took over the city.
A computer virus is a very similar concept. It looks like nothing, or like a useful program that will do something useful for you. But it has a hidden payload which can destroy or delete your personal data or install spyware on your computer. Trojan horses are often called viruses, but unlike true computer viruses Trojans don't replicate themselves.
Many Trojan horse viruses (or simply "Trojans") are actually spyware and they are used to monitor your computer activity and then send that information to someone else (a cyber criminal) without your knowledge.
The spyware that is installed on your computer through the Trojan can log private information such as your credit card numbers and passwords. It might deliver unsolicited pop-up ads or send your browser to a site that you didn't choose, click on, or type in the address for.
Often Trojans will install a 'backdoor', which is a lot like your home's back door - you can get inside the house by bypassing the front door. A computer 'backdoor" allows people into your computer by way of circumventing the usual log in protocol. Hackers can use the backdoor to gain access to your computer and from a remote location they can cause damage or send spam. Since it looks like the damage came from your computer, it can be hard to explain what went wrong if the attack is tracked back to your IP address.
Trojans are usually hidden in programs that you think might be useful. For example, you might visit a free utility site and download a program that you think might be useful to you. When you run the program, the Trojan will come alive and your system will be infected but you won't have a clue unless your anti-virus software picks it up before it can get stuck in.
Trojans can also be spread - like so many other types of malware - through e-mail attachments. These e-mails will usually contain a file that when run infects your computer.
It's important to pay attention to attachments you get with an e-mail, which we all know, but you should pay special attention to attachments that have an extension such as .exe. Sometimes the extensions are well concealed so that they will look like some kind of text file that you can click on and use. Because a lot of you enjoy receiving photos in our e-mail, sometimes a Trojan virus will be embedded in an image file.
Trojans can spread through your operating system if it's vulnerable. Because operating systems control the most basic functions of your computer and computers connect to the Internet through a variety of ports, these ports can create a security risk for you if your operating system isn't functioning as well as it should.
For example, some computers are infected with a Trojan called Sub7. Although some say that it has some valid uses like allowing you remote access to your computer, most claim that it's used for illegal activities. If Sub7 is installed on your computer, someone can access it from a remote location and they can steal credit card numbers by logging keystrokes or other information you type on your keyboard.
If you keep your antivirus software up to date, it will detect and destroy Trojans. While some antivirus programs will require you to initiate a scan of email attachments or other incoming files, it's best to get antivirus software that does this automatically for you. It's not usually much more expensive, but the security and peace of mind it provides is priceless.
Do you think your computer might be infected with a trojan virus? If so you need to take immediate action and install or update your virus removal software right now. Trojan viruses can steal passwords and credit card numbers so make sure you take action right now -> http://www.cpusecurity.com
