TIL this is the polar opposite from the Dutch expression to rub your hands together which means "being happy about a success; being content; expressing happiness" (Ensie, translated by me)
Asking my german partner, they say it's a thing you'd do when plotting something evil, so more negative than positive I guess, but there is no expression to go with it like "hand wringing" or "in de handen wrijven" are common expressions. I would subscribe to it being a plotting thing in Dutch as well, but that also doesn't work with the US English definition and the way that you used it
Do people from the USA also use it this way in a physical sense, rubbing hands together when they are concerned or feeling guilty or is it just an artifact of history similar to "hanging up" a phone? In the Netherlands I've definitely seen rubbing hands for excitement