3.3 Viruses and Worms

Viruses and worms are malicious programs that generally cause damage to the information stored on your computer and attempt to replicate themselves. A virus attempts to replicate itself to documents and executables on your local computer and resources such as network drives that are connected to your computer. The most common viruses seen in the wild today are Microsoft Office macro viruses. Macro viruses usually arrive attached to a legitimate document and execute as soon as you open the document. Once activated, the virus will replicate itself to all the documents it can find and execute its malicious code such as deleting files or modifying the content of your files. Worms are similar to viruses except that they will attempt to replicate themselves over the network. The most common examples of worms are "email viruses" that arrive as email messages, execute and replicate themselves on the local computer and send copies of the message to people in your address book. Frequently, the viruses and worms don't do their damage right away -- they wait until they have the chance to make copies in other locations before they begin to delete files, etc. Because of this, users may use an infected computer for some time before realizing that a virus is present.

All UNT microcomputers should employ virus protection software to protect against damage from viruses. UNT has a site license for McAfee Virus Protection software. This software package must be updated regularly to be effective. Your departmental network manager should notify you when updates are available -- do not hesitate to install these. In addition, you can reduce your risk of virus infection by following these practices:

• Never open or view email attachments or Instant Messenger (IM) links you are not expecting without verifying the contents from the sender.
• Configure applications such as Microsoft Office to prompt you before executing macros.
• Disable JavaScript and VBScript in email clients and web browsers.

To learn about viruses or for additional information, please refer to UNT's Virus Information Page (http://www.unt.edu/security/antivirus/index.html).