This is a good plot, a complicated mystery with several unexpected turns, an affecting romantic sub-plot between the two main characters, and some scary moments.
But it's written by a plodding nerd. The first half is deeply tedious, the second half is a bit better but all the way through we are given far too much detail about uninteresting brand names, leaden conversations, sad and irrelevant technical information about ordinary stuff (I really don't want to know what email software the heroine uses, or how many pixels her new computer has).
It also reinforces the description I once heard of Sweden as "Social Democratic Hell". The novel has a working definition of extreme behaviour as anything that might make a middle-class, middle-aged Swede uncomfortable. Add to that a world view that says the only thing really interesting aspect of life is who runs big companies and a supposedly radical magazine with the dreary title of "Millenium". It's not surprising that, when the author finally gets down to the really bad bits he goes for the nasty, violent sadism, anything less transparently evil would be beyond his literary skills.
The characters are plodding and their behaviour wooden, the central male character spends his life being nice and having his niceness rewarded by various of women wanting to have sex with him. It's like the worst bits of Frederick Forsyth without the interesting practical detail and joined-upness that makes some of Forsyth's writing bearable.