The Self-Diagnosis PC Security Primer

Your computer is stronger than you think.  Learn about some of the most common viruses and the best ways to stop them.

Yes, the rumors are true: The Internet is a wild, woolly place filled with evil forces that want to bring down your PC.

Thankfully, computer security has grown stronger over time, and today your system and Web browsers have fewer security holes than ever. As for the not-so-distant past… well, that was another story.

Below, we look at some of the most wanted computer viruses of the Internet Age —because those who fail to scan, delete and reboot the past are doomed to repeat it.

Melissa, the Matriarch

Way back in the misty dawn of 1999, the first computer virus to capture the world’s attention arrived with a disarmingly innocuous name: Melissa. Dubbed in honor of an exotic dancer, the virus quickly spread itself through email attachments, thus laying the groundwork for a jillion copycats to follow.

Melissa took advantage of a security flaw in Microsoft Outlook to contact the first 50 address book entries of the infected party, enticing each with a vague invitation to open an attached document. It took an update to Outlook and some expensive public education to kill off Melissa for good.

Love in Disguise

The “I Love You” virus arrived in 2001 with a pointed mission: to destroy system files and steal passwords. This worm sent itself through email channels with a brief message of love from a secret admirer. Once downloaded, it wrought considerable damage throughout the Internet. Total price tag: $10 billion. Further security updates to email servers and some PC software were needed to break the back of “I Love You,” despite its many amorous protests to the contrary.

The Conficker Plague

Conficker arrived on the back of another menace known as the Sasser worm. Like its predecessor, Conficker exploited a type of software (known as a Windows remote service) to spread itself without user aid. And like “I Love You,” Conficker was a conduit for further hacks: upon installing itself, it began stealing passwords and installing malicious software (malware), such as  keyloggers (software that tracks every keystroke you make) and back doors (commands that allow hackers to take control of your PC remotely).

Conficker is still around, and can still turn infected PCs into “drones” ready to do the bidding of a far-flung master. The best prevention: keeping your antivirus software up to date.

The world of computer malware is never without emerging new stars worthy of our boos and hisses. Recent entrants like MyDoom and the Storm worm are still considered armed and dangerous, so stay cautious, scrutinize all emails and click only when confident.