Stay on Top of Security Flaws and Protect Your System

Apply patches, monitor updates, and make necessary upgrades to operating systems, software, email clients, and web browsers.
Run antivirus software and keep virus definitions current. Make sure your antivirus software security patches are up-to-date.
Subscribe to advisory and alert lists. These will alert you to any new software updates or patches that are released. Sign up for independent bug-tracking sources, such as the CERT Coordination Center's Advisory List or the BugTraq mailing list, or visit Security Focus regularly.
When identifying vulnerabilities, make sure you don't overlook systems that are perceived as "less critical." Many intrusions enter through seemingly less-critical holes, After the intruders gain access, they will use that entry as a springboard into more critical applications. Remember, anything that is exposed is mission-critical.
As a preventative measure, back up your system and data at least once a month. Create two backups each time, storing them in separate places, one of which is outside your home. And make sure you have an emergency recovery disk as well.
Norton Internet Security from Symantec can help protect you against cybercriminals many other Internet threats.