Please tell me what this is.

[dariush]

I have no idea how this happend and would appreciate any advice on how to get rid of it.

These pictures were taken in a bedroom.

[Jim Katen]

Geben sie einen kontext an.

War das an einer wand? An einem fenster?

[Les]

Nein !

 

[dariush]

That's a wall and the room is held at a warm temperature ~20°C, and i've started ventilating more often.

[Jim Katen]

Sagen sie ihrem jugendlichen Sohn, er soll aufhören, an der Wand zu masturbieren.

[Jerry Simon]

14 minutes ago, Jim Katen said:

Sagen sie ihrem jugendlichen Sohn, er soll aufhören, an der Wand zu masturbieren.

Yeah.  Use a sock.

 

[Jim Baird]

No hablo Aleman de ninguna manera.

[dariush]

Any actual help would be highly appreciated.

[Jim Katen]

Then you need to give us actual information. A few close-ups of white blobs on the wall doesn't tell us anything.

How about some pictures from farther away? Where on the wall is it happening? Is this an exterior wall? What's the weather like over there? When did it show up? What happens if you just clean it up with regular household detergent and a sponge? Does it come back? Have you ever seen it when it's actually wet and dripping? Is it powdery, sticky, hard, smelly, or what?