Information safety

When I was in senior school, I got interested in hacking. I bought lots of books and magazines about information safety and actually did something illegal like stealing the database of one Internet bar and breaking the password of one website’s administrator. So today I want to share with you something about information unsafety.
It is very common that we use the same password for all accounts. That is dangerous. If you register your information in some BBS and it was unfortunately attacked, the hacker would probably get your QQ, email and even ebay-card. So don’t give out your information on some unreliable websites.
Trojans are bothering. Now let’s see how it works. Once your computer is infected with it, it will run secretly and intercept sensitive information like your password and account and send it to the target website or email. There are many different kinds of Trojans, some to steal your accounts of your online games, some to steal your QQ account, some are so powerful that it allows the hacker to monitor your screen, copy and edit your files, record your typing and run commands on your computer. I was often infected with it because I often downloaded unfamiliar files and entered unfamiliar websites of the Internet. So the best way to avoid Trojans is to avoid downloading unfamiliar files and entering unfamiliar websites.
Why is my anti-virus software useless? The anti-virus software has its virus database and when it scans the files it will compare them with the feature codes in its virus database to see if it is similar. So if you add some codes that will not affect the function in the virus and Trojans which will make them “unfeatured”, the anti-virus will not recognize them and let them go. So updating your virus database is necessary but not trustable.
I will go on this topic next time.