MALICIOUS SOFTWARES

Malicious Software: Viruses, Worms, Trojan Horses, and Spyware

Have you ever picked up a cold or the flu from another human? Probably. You then spread it to two or three other people through touch or association. Those people spread it to two or three more people each. Pretty soon it seems that everyone on campus or at work is sick. That is how computer viruses are spread. You copy a file from an infected source, use the file, and maybe send it to friends or associates. The virus is now on your computer and spreads to files other than the original. You then send the same or even a different file to a few friends and their computers are infected.

A different type of malware called worms can also destroy data on computers or clog network systems with software-generated electronic transmissions. Worms are similar to viruses in that they c

an create additional file copies on a computer and generate emails to other computers with the infected file attached. Worms differ from viruses because they don't need human intervention to spread from one computer to another.

Trojan horses cause problems because they force a computer system to perform unexpected operations, often to the detriment of the system and the user. This type of malware is usually masked in email messages although it can be stored on Web sites. This table gives you examples of malicious code that are spread through vulnerable Internet-connected systems.

Not all spyware is damaging to a computer system. It is a popular method for some Web sites to monitor how users navigate through a site, providing critical information that the Web designers and developers can use to improve the site. Unfortunately, some spyware is becoming a popular way for hackers to install malicious code on computers and allows hackers to infiltrate the unsuspecting computer.

Whether you use a stand-alone PC or your computer is attached to a network, you're just asking for trouble if you don't have antivirus software. This type of software checks every incoming file for viruses. Not if, but when, you receive an infected file, the software alerts you to its presence. You can choose to delete the file or "clean" it. Make sure you update your antivirus software every 30 to 60 days, because new viruses are constantly being written and passed around. Some antivirus software companies now make it very easy to keep your antivirus software current through online updates. McAfee.com will detect when you are online and notify you when new updates are available. With a few mouse clicks, you download the software to protect against the newest viruses.

Web-enabled and e-mail-enabled cell phones are now being targeted as a way to spread viruses.

As cellular phones morph into computerlike "smartphones" able to surf the Web, send e-mail and download software, they're prone to the same tribulations that have waylaid computers over the past decade. "We should think of cell phones as just another set of computers on the Internet," said Stephen Trilling, director of research at antivirus software maker Symantec Corp. "If they're connected to the Internet they can be used to transmit threats and attack targets, just as any computer can. It's technically possible right now."" Associated Press, April 1, 2002.

If you connect to the Internet with a cable modem or DSL you are much more vulnerable to hackers on your home PC than if you connect with a dial-up modem. That's because you are always connected, with a permanent IP address, which makes it easier for hackers to find you. The only smart thing to do is keep your software up-to-date and include firewall protection.

NOOPUR GARG
BBA/4536/07