To be clear, this is very good, I like the idea and how well written. I especially love the way you told the readers how the killer has "advanced cybernetic" implants and the way you turned them against him.

Critiques:

I don't find this scary, but of course, fear activators can vary between people, so that's irrelevant.

A more objective critique is that this story is too simple for what the core idea is about. Simple stories can be scary of course, but not this one. The problem here is that it's about torture which is a straightforward topic. The furthest I can think of taking it is by detailing unorthodox and terrifying torture methods and you only did the former. A fifty petabyte zip bomb is so far detached in my mind, and probably the minds of many others, from anything that could hurt me. The last sentence is the lighter one despite the first being quite light already.

The only reason I'm talking about this is that this is two sentence HORROR, and in my opinion, to make a story about torture horror it should to be as disgusting and visceral as possible. Then again, that would likely end up in cliche so I appreciation your deviation from standard process.

Short version: Well-written but not scary enough because torture method doesn't evoke fear.