---
title: "What is ransomware? | Daniel Christensen"
canonical_url: "https://danielchristensen.no/en/glossary/losepengevirus"
last_updated: "2026-09-02T13:55:00.035Z"
locale: en
meta:
  description: "Malware that encrypts your files and demands payment to unlock them. Hits companies hardest."
  "og:description": "Malware that encrypts your files and demands payment to unlock them. Hits companies hardest."
  "og:title": "What is ransomware?"
---

[← All terms](https://danielchristensen.no/en/glossary)Glossary

# Ransomware

Malware that encrypts your files and demands payment to unlock them. Hits companies hardest.

Ransomware encrypts files and systems and demands payment, usually in cryptocurrency, to unlock them again. Modern variants also steal the data first and threaten to publish it, so-called double extortion.

For companies this is one of the most expensive incidents there is, and the way in is almost always one of the other things in this glossary: phishing, leaked passwords or unpatched systems. The best defense is boring and effective: updated systems, two-factor authentication, and backups that actually get tested.

An attack rarely starts with the encryption. The attacker is typically inside for days or weeks first, looking around, collecting more access and working out where the backups live. Those get deleted or encrypted first, precisely because they are the one thing that lets a victim say no. The encryption itself is the last step, not the first.

Paying is not a plan. You have no guarantee of getting the data back, you finance the next attack, and whoever stole your data still has it. What actually helps is dull: backups kept out of reach of the network being attacked, and tested by genuinely restoring something from them. A backup nobody has ever restored from is an assumption, not a plan.

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