Possible white fungus on bark

[Medija]

Hello, everyone.

I'm a new member here and a pretty new orchid owner as well.

Just yesterday i wanted to rearrange my orchids and noticed that one of them had this white stuff on the bark.
The orchid is healthy, is having new leaves and the roots look okay, too. None of my other neighbouring orchid have this.

Im wondering is this some sort of fungus that got to my orchid? Did i overwater it? And most importantly, how to get rid of it without damaging my orchid too much?

Hoping to get this fixed since this is one my oldest orchids and this is the first problem with it.