Ransomware
Ransomware doesn't have to steal a thing: it just locks you out of your own files and charges you for the key.
By Greg Goodwin · Published July 3, 2026 · Updated October 24, 2026

Cheat Sheet
- Ransomware is a type of malicious software that encrypts a victim's files or locks them out of their own systems, with attackers demanding payment, typically in cryptocurrency, in exchange for restoring access.
- Ransomware commonly spreads through phishing emails, malicious attachments, or exploiting unpatched software vulnerabilities, often requiring only a single successful entry point into a network.
- "Double extortion" ransomware attacks, an increasingly common tactic, involve attackers both encrypting a victim's data and separately threatening to publicly leak stolen sensitive information unless payment is made.
- Ransomware attacks have increasingly targeted critical infrastructure, hospitals, and large organizations, since these targets often face significant pressure to pay quickly in order to restore essential operations.
- Cybersecurity experts and law enforcement agencies generally advise against paying ransomware demands, both because payment doesn't guarantee full data recovery and because it can encourage further attacks.
- Regular, tested data backups stored separately from the primary network are widely considered one of the most effective defenses against ransomware, since they allow recovery without needing to pay attackers at all.
The 60-Second Version
Ransomware is a type of malicious software that encrypts a victim's files or locks them out of their own systems, with attackers demanding payment, typically in cryptocurrency, in exchange for restoring access. Ransomware commonly spreads through phishing emails, malicious attachments, or exploiting unpatched software vulnerabilities, often requiring only a single successful entry point into a network. "Double extortion" ransomware attacks, an increasingly common tactic, involve attackers both encrypting a victim's data and separately threatening to publicly leak stolen sensitive information unless payment is made. Ransomware attacks have increasingly targeted critical infrastructure, hospitals, and large organizations, since these targets often face significant pressure to pay quickly in order to restore essential operations. Cybersecurity experts and law enforcement agencies generally advise against paying ransomware demands, both because payment doesn't guarantee full data recovery and because it can encourage further attacks. Regular, tested data backups stored separately from the primary network are widely considered one of the most effective defenses against ransomware, since they allow recovery without needing to pay attackers at all.
The Long Version
Locking, Not Necessarily Stealing
Ransomware works by encrypting a victim's files or otherwise locking them out of their own systems, rendering data inaccessible without a specific decryption key held by the attacker, who then demands payment, typically in cryptocurrency due to its relative difficulty to trace, in exchange for restoring that access, a fundamentally different attack model from data theft alone.
How Ransomware Actually Gets In
Ransomware commonly spreads through phishing emails designed to trick a recipient into opening a malicious attachment or clicking a malicious link, or through exploiting unpatched software vulnerabilities, often requiring only a single successful point of entry into an otherwise well-defended network to spread and cause significant damage.
The Growing "Double Extortion" Tactic
An increasingly common tactic known as double extortion combines the traditional encryption-based attack with a separate threat: attackers steal sensitive data before encrypting it, then threaten to publicly leak that stolen information unless payment is made, adding significant additional pressure on victims even if they have reliable backups that would otherwise let them avoid paying simply to restore access.
Why Experts Discourage Paying, and What Actually Works
Cybersecurity experts and law enforcement agencies generally advise against paying ransomware demands, since payment doesn't guarantee full data recovery and directly incentivizes further attacks against the same or other victims. Regular, properly tested data backups, stored separately from the primary network so they can't also be encrypted in the same attack, remain widely considered one of the most effective practical defenses, since they allow full recovery without needing to pay attackers at all.
Why People Care
Ransomware has become one of the most financially damaging and disruptive categories of cyberattack, increasingly targeting critical infrastructure and essential services, making basic awareness of how it spreads and how to defend against it directly relevant to both individuals and organizations.
Glossary
- Encryption (in ransomware context)
- The process ransomware uses to lock a victim's files, making them inaccessible without a specific decryption key held by the attacker.
- Double extortion
- A ransomware tactic combining data encryption with a separate threat to publicly leak stolen sensitive information.
- Phishing
- A common method used to spread ransomware, tricking a victim into opening a malicious email attachment or link.
- Backup
- A separately stored copy of data, widely considered one of the most effective defenses against ransomware.
- Cryptocurrency ransom
- The typical form of payment demanded by ransomware attackers, chosen partly for its relative difficulty to trace.
Go Deeper
More to Explore
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- Two-Factor Authentication
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- Encryption
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- Password Security
The single biggest security upgrade most people could make costs nothing and takes ten minutes: stop reusing passwords.
- Data Breaches
Most of the damage from a data breach doesn't happen the day it's discovered — it happens months later, when the stolen data finally gets used.