The Federal Trade Commission says beware of pop up ads, online ads or emails telling you about free security scans. The ads usually claim that there are already problems on your computer.

The free scan claims to find all sorts of problems, then urges you to spend at least 40 dollars or more on security software. After you buy the software, the program tells you, your problems are fixed. The FTC says, you may have never had any problems at all.

Officials also say, you may have installed a program that will be harmful to your computer.

For a list of what to watch for in these security scan ads, click h ere.