Blueballs (Also known as Virus.Win32.Blueballs) is a virus on Microsoft Windows. It is not as malicious as other viruses, as this virus' payload is cosmetic, and does not attempt to destroy the computer.
The virus only activates on January 1st. When run, blue balls start appearing on the monitor, multiplying rapidly. However, this is a merely cosmetic payload, and nothing more happens. The user can still use the computer normally when the payload is running. Even if the payload covers the icons on the desktop, the user can still click on the icons.
The payload also has a display error, as it appears that the virus was made for an 800x600 resolution. If the virus is used on a computer with a higher resolution, the virus will appear in the upper left corner of the screen instead.
The payload can be stopped by simply resetting the computer, or terminating the program in Task Manager.