Carnegie Mellon University

What are Viruses, Worms and Breakins?

Recent events indicate a definite progression in the sophistication and seriousness of viruses and worms.

Similar to a biological virus, a computer virus piggybacks on top of other programs or documents in order to become executed, infecting the machine. Viruses can be carried along via e-mail or other files that you have downloaded or transferred. Up to date anti-virus software or special removal tools are used to detect and clean viruses.

There are also malicious programs called worms. Worms, unlike viruses, spread by sending copies of themselves across the network, exploiting vulnerabilities in programs on other computers. Up to date anti-virus software or special removal tools are used to detect and clean worms.

Breakins are attacks that specifically target your computer. Breakins can occur through a file you download and run, or via some security hole exposed through a network connection. Breakins are NOT always detectable through up to date antivirus software and typically, there is no automated clean up method. Most often it is recommended or even required that the machine be reformatted and reinstalled since determining the extent of the breakin is usually very difficult.

In addition to the virus and worm epidemic, Microsoft has recently published a number of security alerts and patches for operating system vulnerabilities. When a computer is left un-patched, these types of vulnerabilities allow a remote attacker to take control and run any arbitrary code of their choosing. Unfortunately, this trend may become more popular since malicious attacks now breakin into computers for profit.

So, how do you protect your computer from worms, viruses and other attacks?  Unfortunately, there isn’t one sure-fire cure. Anti-virus software combats worms and viruses, but it does not always detect if your machine is vulnerable to or has been compromised by a malicious attacker.



Webopedia; The Difference Between a Computer Virus, Worm and Trojan Horse

US-CERT; Recovering from Viruses, Worms, and Trojan Horses

Carnegie Mellon University, Computing Services; Secure Your Computer