That is some variety or another of a “torx star” head. They vary in size and are listed as TS-10, TS-15, etc. your best bet would be searching torx star and buying a set of bits to try out various sizes.
Pick up the IFix it screw set, it has socket style bits that will fit that, plus most of the goofy screws in electronics, I'm a broadcast engineer and that set is awesome for work and hobby electronics work.
Edit: I just looked at their site and seems like they've grown a bit in the last ten years, they have many sets but here's a link, they definitely have what you need https://www.ifixit.com/Tools
thanks, this might be just the comment I needed!
Some of the screws are sunk into a very deep hole (~60mm), so it would be tough to cut a slot into those. But i'll give it a try on one of the more exposed screws, just to see if that gets me anywhere.
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.
OP, note that this is an external Torx; most tools you'll find are bits, because they're more common. You want a socket set. Something like this has both, but you want the top row for your case.
Hard to say without a scale reference, but if it's small, I very small might very will be a proprietary fastener for higher security applications. If it's a Tesla battery pack, then the epr 5-point torx is a good candidate. If it's an apple device then searching pentalobe might get you farther.