They're especially dangerous when they infect removable media like flash drives.
And they travel across networks (and possibly across wireless networks) to infect shared resources.
Boot into Safe Mode and run a virus scan from there. Safe Mode should keep a virus from loading up and going active.
Best to also have a '2nd opinion' run a scan. The worst kind of infections (rootkits) can hide themselves from an AV scan and even alter how an AV program works in a malicious way.
Download and install Malwarebytes Anti-Malware 1.46
and run that from Safe Mode.
Most of the major security players have a free online scan utility too.