Computers across the world were locked up and users’ files held for ransom when dozens of countries were hit in a cyberattack that targeted hospitals, companies and government agencies.
Here’s a look at how malware and ransomware work and what people can do if they fall victim to attacks.
Malware is a general term that refers to software that’s harmful to your computer, said John Villasenor, a professor at the University of California, Los Angeles.
Ransomware is a type of malware that essentially takes over a computer and prevents users from accessing data on it until a ransom is paid, he said.
In most cases, the software infects computers through links or attachments in malicious messages known as phishing emails.
“The age-old advice is to never click on a link in an email,” said Jerome Segura, a senior malware intelligence researcher at Malwarebytes, a San Jose-based company that has released anti-ransomware software. “The idea is to try to trick the victim into running a malicious piece of code.”
The software usually is hidden within links or attachments in emails. Once the user clicks on the link or opens the document, their computer is infected and the software takes over.
“Ransomware, like the name suggests, is when your files are held for ransom,” said Peter Reiher, an adjunct professor at UCLA who specializes in computer science and cybersecurity. “It finds all of your files and encrypts them and then leaves you a message. If you want to decrypt them, you have to pay.”
The ransomware encrypts data on the computer using an encryption key that only the attacker knows. If the ransom isn’t paid, the data is often lost forever.
