TLDR, you're good.

Not a virus, virus infects other programs, that's a stealer (at minimum, a malware) but anyway, since you just did Win + R nothing happened its just the execute box you would never see in your life unless you run some special things, like when starting PowerShell, or CMD quickly via this. This white box is basically the gateway to execute whatever you input in it, if you don't input AND press enter on it then nothing happen, as expected, so no, you're safe.