How to secure your computer

Written by: George Rhoten

Due to the default settings on most operating systems, most computers aren't secure enough from viruses or hackers. This page contains some guidelines to secure a computer. The information on this page is targeted towards people with medium to advanced computer skills. If you have problems with using a command prompt, you should consider getting help from someone else that can secure your computer for you.

Here are some more links to other security related web sites.

• SANS - FBI The Twenty Most Critical Internet Security Vulnerabilities
• Gibson Research for ShieldsUP!, which tests and reports network security holes on your computer.
  

Common Security Guidelines

Regardless of the computer you should always follow these words of wisdom:

• Restrict the permissions on who can read or write to your files, especially over a network.
  • Some worms can spread through publicly writeable shares. Reduce the number of files that other people or programs can write to, especially executables.
  • Never share your whole hard drive. Password files and cached mailboxes should never be viewed by anyone except yourself.
  • Password protecting your files is always a good idea. Using the "Authenticated Users" on a Windows domain and "textintl" group on Unix are okay for authentication. The "Everyone" Windows domain group and the "other" group on Unix is usually a bad idea to use.
  • Limit the number of shared directories that can be written by other people. One empty directory is good enough to allow other users to write to your computer. It makes it easier to detect when random people or viruses have written to your hard drive.
• If you don't need a service running on your computer, turn it off. If a service isn't available, then no one can use the flaws of the service against you. You also don't have to worry about security updates because it isn't running.
• Keep up to date with security fixes, or at least the service packs.
• Install anti-virus software, if available.
• Don't detach or run attachments from strangers. Never run executables from an e-mail, even from friends. It could be from a e-mail worm.
• Increase the security settings of your e-mail and web client.
• Consider installing a firewall on your computer, especially on your home or mobile computer. It's a good backup plan in case you have improperly secured your computer.
• Don't give out your password to anyone else. If you're not the only person with the password, you have lost the control over the security.