---
title: Usynlig Fjende Book Release
description: New book Usynlig fjende explores cybercrime, hacker attacks, and hybrid threats, offering real-world insight into today’s digital risks.
---

[What's new ](https://www.csis.com/whats-new)

# [Usynlig Fjende Book Release](https://www.csis.com/whats-new/usynlig-fjende-book-release)

 Written by [CSIS](https://www.csis.com/whats-new/author/csis) | Feb 25, 2026 11:25:33 AM

##### *We are proud to announce that our colleague Jan Kaastrup has published the book "Usynlig fjende" together with Michael Sjøberg and Ida Nyegård Espersen. Together, the authors take readers behind the scenes of real cases, cyberattacks, and their very real consequences -offering rare insight into the inner workings of the IT-criminal underworld. Written for a broad audience beyond technical specialists, "Usynlig fjende" makes complex threats accessible and sheds light on the hybrid risks shaping today’s security landscape. ** *

[Buy the book](https://www.saxo.com/dk/usynlig-fjende_bog_9788740023947)

[Listen to the audiobook](https://lydbogbob.dk/lydboeger/faglitteratur/usynlig-fjende/) 

[View full post](https://www.csis.com/whats-new/usynlig-fjende-book-release)

```json
{
  "@context" : "http://schema.org",
  "@type" : "BlogPosting",
  "author" : {
    "@type" : "Person",
    "name" : "CSIS"
  },
  "dateModified" : "2026-03-26T21:09:16.193Z",
  "datePublished" : "2026-02-25T11:25:33Z",
  "headline" : "Usynlig Fjende Book Release",
  "image" : {
    "@type" : "ImageObject",
    "height" : 897,
    "url" : "https://www.csis.com/hubfs/Jan%20Kaastrup%20and%20Michael%20%20Sj%C3%B8berg.jpg",
    "width" : 1920
  },
  "mainEntityOfPage" : "https://www.csis.com/whats-new/usynlig-fjende-book-release",
  "publisher" : {
    "@type" : "Organization",
    "logo" : {
      "@type" : "ImageObject",
      "height" : 60,
      "url" : "/hs/hsstatic/content_shared_assets/static-1.4092/img/default-amp-logo.png",
      "width" : 60
    },
    "name" : "What's new"
  }
}
```