EDIT: I believe I found the answer, it's something turned by this: https://ctatools.com/products/5065
Found some trash on the street that i'd like to take apart, but this screw is in my way.
It's like a hex bolt, but with 5 sides, and rounded (a bit like flower petals).
Here's another picture from the top:
I tried turning it with various tools (hard to get pliars in unfortunately), no success so far. The material is very soft, which doesn't help..
Torx is 6-pointed tho
People often call variants with other numbers of points "torx" as well. Torx is technically a brand (a trademark) and in that sense, if we were being strict, wouldn't include basically any of the commin TN 6-point driver sets out there, e.g. Wiha and Wera sets. But everyone just says "5 point torx" and so on.