When handling Internet files, how can I be safe?

For information about security practices when handling Internet files, see the list of Knowledge Base documents below:

• Clicking links:
  
  
  • What are phishing scams and how can I avoid them?
  • If I use instant messaging software, how can I keep my computer secure?
  • At IU, how can I protect my computer from an email attachment infected with a virus?
  
  
• Instant messaging:
  
  
  • If I use instant messaging software, how can I keep my computer secure?
  • What should I do if my computer is infected with an instant messaging (IM) Trojan?
  
  
• Email messages and attachments:
  
  
  • At IU, how can I protect my computer from an email attachment infected with a virus?
  • At IU, what types of attachments are blocked from my email account?
  • What is email fraud, and what should I do about it?
  • What is spam?
  
  
• Internet files and browsing:
  
  
  • What are secure web sites and SSL certificates?
  • In my web browser, how do I know if a site is on a secure server?
  • What is spyware or adware, and how can I remove it?
  • If I use file-sharing software, how can I keep my computer secure?
  
  
• Running as a limited user:
  
  
  • What is the principle of least privilege?
  • In Windows, how can I run an administrator task from a non-admin account?
  • In Unix, what are the sudo and su commands?
  • In Windows, why should I avoid running my computer as an administrator?
  
  
• Virus scanning:
  
  
  • Using Symantec/Norton AntiVirus Corporate Edition in Windows, how do I immediately scan a file, folder, or drive for viruses?
  • Using Norton AntiVirus for Mac OS or Mac OS X, how do I immediately scan a file, folder, or drive for viruses?
  • For Symantec virus protection software, what are my options for updating the virus definitions?
  • In Symantec/Norton AntiVirus, how do I check the version number of the program and the age of the virus pattern update?