By Richard Heller
For a long time now, I have been telling you of the importance of security while you are connected to the Internet. When you go online through a high-speed connection such as ADSL or a cable modem, your computer is ALWAYS open to attack by others wishing to do mischief.
When you connect through cable or ADSL, you are actually becoming part of a network, just as your computers are connected together in your office. The Internet provider supplies you with a static IP address. This means that your computer has the same identification number on the network all the time; this is how the system knows how to deliver the e-mail and web pages to the correct computer.
The problem with this is that a hacker can find your computer by entering numbers much the same way that telemarketers dial, that is, they will dial 555-1212, then 555-1213, then 555-1214, etc. until they find a number that answers. Once they have located your computer in this manner, they know that it will always be at the same number, and they can then start to see what they can access.
One new way of causing problems is not by placing a virus on your computer but rather by sending you e-mail or a file that contains damaging program code. E-mail programs such as Microsoft Outlook or Outlook Express allow you to preview your messages just by clicking on them. The problem with this is that the hackers have discovered a way to imbed a virus that can be activated simply by previewing e-mail.
Another new tactic is to send you e-mail that contains a SCR or PIF file. The SCR file is supposed to be a screen saver; the PIF file tells the computer how to run a program. Virus scanners usually ignore these types of files, so hackers are using them to send Trojans and worms.
A program known as Visual Basic causes another new danger. This is a program that allows you to write your own Windows-based programs. The hackers have discovered that by writing a Visual Basic Script (VBS), they can do almost anything to your computer.
I recently had a call from a business in Rockton that was having problems with one computer printing to a network printer along with programs running slowly. They said that things had worked fine until about a month ago. Upon examining the computer, I discovered that a VBS program was being loaded when the computer was started. The sole purpose of this program was to disrupt the computer network. After the program was removed, things were again back to normal.
The program entered the computer from their cable modem. Insight and the @home service install a firewall program on your computer to block these attacks; other cable providers may not. You should check with your provider to see whether one was installed. If you dont have one, you can download ZoneAlarm from www.zonelabs.com, or you can purchase Norton Internet Security or a similar program.
Richard Heller is an independent computer specialist who specializes in repairs, installation, upgrades, technical support, Internet sharing, data recovery and diagnostics. If you have any computer or service-related questions, please send them to The Rock River Times or e-mail email@example.com.