Ever wonder what the difference is between a virus, spyware, trojan, or worm? Here is a brief description of each type of computer attack and what you can do to avoid these infiltrations.

Virus - A malicious program designed to infect files on a single computer. Viruses are typically small programs written to execute and replicate themselves in order to alter the way a computer operates, without the permission or knowledge of the user.

Spyware – Software that secretly gathers information about a person or organization, often their Internet browsing habits, but can also be designed to interfere with or control other functions of a computer’s operation without the knowledge or permission of the user.

Trojan (Trojan horse) - An imposter in disguise. A trojan is a file that appears to be something desirable, such as a piece of software, but is actually malicious. Trojans do not replicate themselves, but when triggered, they allow unauthorized access to a user’s computer. Important data from the machine can be lost or stolen, usually unbeknownst to the user.

Worm – A malicious program designed to spread from one computer to another through a network. Worms replicate themselves from system to system. This is in contrast to a virus which requires the spreading of an infected host file. Worms replicate themselves without the use of a host file.

See the Symantec Web site to learn more.

Mac Myth

Many Mac users operate under the assumption that when it comes to security, their system is immune to the types of malicious computer attacks discussed above. Recently, there was a security alert issued to Mac users advising them of a trojan horse found in pirated copies of Apple’s iWork ‘09 application suite.

In addition, there have been a few examples of MacOS servers being penetrated through various misconfigurations. It serves as a reminder to all users to take great care in how they alter their computers from their basic configurations, even Mac users.

Prevention

• Never run attached files or programs, or visit Web sites that are linked to suspicious e-mail messages.
• Avoid downloading files from unknown and untrusted sources.
• Install anti-virus or anti-spyware software and keep it up-to-date. Stony Brook students, faculty, and staff can download Symantec Endpoint Protection (anti-virus software) from Softweb to help protect their machines. See the Symantec AntiVirus Help page for more information.
• Do not download pirated software. It might contain a trojan.
• Run your Windows, Apple, and Unix/Linux software updates on a regular basis so your computer system has the latest fixes and patches to keep running at optimal performance.
• Keep your Internet browser up-to-date.
• It is recommended that you do not install more than one anti-virus software program on your computer. This can cause conflicts between the two programs and trigger false virus alerts.
• If you suspect that one of your files or programs is infected, it may not be sufficient to remove that file. Sometimes, the safest recovery method starts with a reformat and a clean installation. Trojans may also modify installed applications, so programs should be reinstalled using their master discs, not from backups.