For almost a decade — and counting — ransomware has been a massive security headache for individuals and businesses alike. More than just some malicious codes, it’s now considered a type of terrorism or a weapon of war.

The good news is that you can prevent ransomware without spending any money. You only need to understand how it works and avoid it.

This post will explain ransomware in layperson’s terms and how you can keep yourself safe from this scam. The key is to pay attention and take the issue seriously.

Dong’s note: I originally published this post on May 24, 2018, and updated it on November 5, 2022, with more practical information on how to stay safe.

What is ransomware, and why is it so bad?

Ransomware is a piece of malicious software that, when executed, encrypts — or locks — popular file types, causing you to be unable to open documents or even run applications.

The malware then displays a message with instructions on how you can pay — usually via cryptocurrencies — to get your files back.

When you see that dreadful message, you better hope you’ve had an alternative way to restore your data — via particular backups. Otherwise, chances are you will never get your files back. It’s just too late.

That’s because the ransom tends to