How can you reduce the risk of another infection?

Dealing with the presence of malicious code on your computer can be a frustrating experience that can cost you time, money, and data. The following recommendations will build your defense against future infections: use and maintain anti-virus software - Anti-virus software recognizes and protects your computer against most known viruses. However, attackers are continually writing new viruses, so it is important to keep your anti-virus software current (see Understanding Anti-Virus Software for more information).

change your passwords - Your original passwords may have been compromised during the infection, so you should change them. This includes passwords for web sites that may have been cached in your browser. Make the passwords difficult for attackers to guess (see Choosing and Protecting Passwords for more information).

keep software up to date - Install software patches so that attackers can't take advantage of known problems or vulnerabilities (see Understanding Patches for more information). Many operating systems offer automatic updates. If this option is available, you should enable it.

install or enable a firewall - Firewalls may be able to prevent some types of infection by blocking malicious traffic before it can enter your computer (see Understanding Firewalls for more information). Some operating systems actually include a firewall, but you need to make sure it is enabled.

use anti-spyware tools - Spyware is a common source of viruses, but you can minimize the number of infections by using a legitimate program that identifies and removes spyware (see Recognizing and Avoiding Spyware for more information).

follow good security practices - Take appropriate precautions when using email and web browsers so that you reduce the risk that your actions will trigger an infection (see other US-CERT security tips for more information).

As a precaution, maintain backups of your files on CDs or DVDs so that you have saved copies if you do get infected again.

References

Recovering from a Trojan Horse or Virus

Before You Connect a New Computer to the Internet

Author: Mindi McDowell / Copyright 2005 Carnegie Mellon University.