In terms of sheer frequency, the top spot on the list of security threats must go to viruses. The after-effects of viruses are so dangerous that they take second place.
Another related threat is the worms that turn PCs into remote mail servers and send cascading volumes of e-mails that cause denial of service attacks. Hacks, and application-specific hacks in particular, have become even smarter. Phishing, or identity theft, is most commonly targeted at bank customers but everybody should be alert to it. And bank users receive an e-mail as if from the bank asking for their log-on and password posing another significant threat.
Learn about these and other computer and Internet security threats from an expert