Below is a classic example of Scareware. This malicious software is used to scare the user into calling for help due to their fake problem. The telltale sign that this is fake is the tech support phone number. Do not trust tech support from unknown entities.
If you have a computer problem at work, call Keystone. At home, call the most tech savvy friend or family member you know. Scareware may also include loud alert noises from your computer speakers. The pop up will not go away by simply closing the internet browser. Logging off the computer session and then logging back in will typically makes this pop up go away.