With the popularization of broadband Internet connection, more and more users have their Internet connection active during all the time the computer is on. Even if you are not in fact accessing the Internet, the computer is connected. This way, such user tends to be more worried about invasions than the users who access the Internet through dial-up connections or users who don't have access to the Internet.

To start with, it has to be understood that a hacker can only invade your computer if you "let" him/her do it. For instance, a hacker can only invade your computer using a backdoor like Netbus and Back Orifice if you have that type of program installed in the computer. That type of program transforms your computer in a server, making it possible for anybody in the world to invade your computer and read your files (with the appropriate tool, of course). But who is crazy enough to install a program like type in the computer? Nobody, of course. They usually come as "Trojan Horses", that is, disguised as cool screen savers that a friend (a friend?) has sent you. Luckily, now all antiviruses recognize and remove that type of program, hence the importance of having an updated antivirus program in the computer.

Pay attention because nowadays Trojan Horses come in fake e-mails supposedly coming from banks and stock brokers. For example, in you have a checking account on Citibank and receives a fake e-mail saying that you should update your data and provides a direct link to do so, you might be tempted clicking on the link or even installing the software that may have come attached to this fake e-mail. DON'T DO SO! This link or software will steal your passwords and banking data! This technique, also known as phishing, is becoming more and more popular.

The best piece of advice? Don't click on links nor install softwares that come from people you don't know. Since a lot of people nowadays know about phising, people behind these scams are now sending e-mails saying that someone you love sent you an e-card or something like that, asking you to click on the provided link for you to read the lovely message. Don't be silly, don't click on these links! It's a Trojan Horse!
 
But, besides Trojan Horses, what other type of procedure a common user may unintentionally perform which will let his/her computer become exposed to invasions? File sharing. Let's explain more about this.