COM 125 - Entry #6: Protection & Prevention Methods

The following are some ways of protecting your computer in the following areas:
1) Email
The computer viruses that have historically caused the most damage (such as Melissa and LoveLetter) are those that spread via e-mail. A basic plain text e-mail message is unable to transmit a virus. It is attachments to e-mail messages that potentially contain the hazard. Unexpected attachments or those from unknown senders should be deleted. Attachments sent from known and trusted sources may also contain viruses -- it's a good practice to contact the sender to confirm that the attachment is legitimate before opening.
Tips to help avoid contracting and spreading e-mail viruses: Do not open or run unknown attachments!
If you are unsure about what an attachment is or what it does, leave it alone. If you have determined that an attachment is a virus, delete the email and the attachment. Documents and spreadsheets can contain viruses!

Microsoft Word documents (.doc files) and Excel spreadsheets (.xls files) can potentially contain a type of virus known as a macro virus. Do not open these types of attachments unless you have enabled macro protection in Word and Excel. For detailed instructions on how to enable macro protection see Word-Enable Macro Protection and/or Excel-Enable Macro Protection. With macro protection enabled, Word or Excel will give you the option to enable/disable a macro for each document/spreadsheet you open. In general, you should open documents with macros disabled unless you know specifically what the macro does.
Pay particular attention to executable attachments!
Common extensions for executable files are:
.exe (executable files)
.vbs (Visual Basic scripting files)
.js (Javascript files)
.com (command files)
.bat (batch files)
.reg (registry files)
The only file types that are definitely safe are those that end with:
.txt (text files)
.rtf (Rich Text Format files)
Look for unexpected or multiple file extensions
If the subject line or the body of an e-mail states that the attachment is a certain type of file or if the file icon implies a certain type of file and the file extension does not match, delete the file. Also delete the file if it has multiple extensions such as picture.gif.exe. This is not really a picture file but an executable program that could potentially be a virus. If you trust the sender, contact that person to determine what you were supposed to have received.

2) Sharing Network Drives
Any time that you share a directory or a hard drive so that others on your local network can access them, you are opening yourself up to the risk of infection or malicious tampering. For this reason, we recommend that you do not share any of your files or folders over the network without the approval of your local network administrator. If you do choose to share your resources over the network, here are some precautions to take.
Share as little and as safely as possible.

1. Do not share your entire hard drive.
2. Do not share your root (C:\) directory or any of your Windows directories.
3. Don't give "Write" access! Set the access permissions to your shared folders to "Read." With "Read" access, others can still copy and see files in your shared directory but they cannot make changes to your files or delete them and if they can't, then neither can a virus.
4. Password protect your shared folders! Protecting your shared directories with passwords will limit access to only those individuals with whom you have entrusted the password.

Antivirus programs can be configured to regularly check your computer or even your incoming e-mail attachments for viruses. Because viruses are being constantly created or changed, it is important to use a program that provides regular updates. University Affiliates can obtain Symantec Antivirus free of charge by visiting DoIT's Security Site .Apple users should note that there are currently no wild viruses for MacOS 10, and thus at present Antivirus clients for MacOS 10 are unnecessary burdens.
a. Update your antivirus program regularly:
New or modified viruses are regularly unleashed on the Internet. Updating your antivirus software so that it contains the latest virus definitions will decrease the likelihood that you are affected by a new type of virus. Here are links to the virus updates for the most popular anti-virus programs.
1) Norton Anti-virus for both Mac and PC
2) McAfee Anti-virus for both Mac and PC

b. Check for security updates for your system:
Microsoft and Apple both regularly release security updates that fix security holes in the Windows and in the Macintosh operating systems. These holes make your system more susceptible to viruses and allow them to be spread more easily.