Trojan hijack

Received popup yesterday on Windows10:

"BSOD e83rhx Virus Detected. Trojan Backdoor HiJack 365838d7f8a4fa5. Breach - 45jz2npw. All programs have been blocked phone....." [phone number removed]

I closed the PC. Restarted and did full Norton Scan. Nothing detected. Was this a scam - or what?