Here are some signs your computer is infected, tapped to serve as part of "botnet" armies run by criminals:
• You experience new, prolonged slowdowns. This can be a sign that a malicious program is running in the background.
• You continually get pop-up ads that you can't make go away. This is a sure sign you have "adware," and possibly more, on your machine.
• You're being directed to sites you didn't intend to visit, or your search results are coming back funky. This is another sign that hackers have gotten to your machine.