If you didn't install the program, it's most likely a virus/malware. Did you scan for viruses using your installed AV?
You should do that and scan/remove any viruses found. In addition it's a good idea to download the free MALWAREBYTES antispyware program from malwarebytes.org and scan/remove all spyware viruses found. Power off your computer for 5 minutes. Reboot and retest your computer and see if it's gone. If it is, you had a simple spyware virus most likely and you're good to go.
90% of the computers I see in my shop contain spyware viruses; so it's a pretty good bet that's what you have.