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..
And it's an inverted torx (with 5 points) as usually the screw driver is male and the screw head is female - I think that's the right nomanclature.
https://germantoolblog.com/2017/06/01/torx-and-its-many-variations/
Oh ffs I didn’t notice it was inverted from the pics. Good catch. Someone really doesn’t want you to open that shit OP.
true, looking at second pic it's very hard to make out. I tried to capture it on the first picture, but it's not that good
I think I found it, it's this kind: https://ctatools.com/products/5065x12
yeah, it is inverted (or "external" torx according to your link). They also made sure to sink the screws into a whole where no pliars will fit...