What is ransomware? How these attacks work and how to recover from them
Ransomware is a form of malicious software (or malware) that, once it’s taken over your computer, threatens you with harm, usually by denying you access to your data. The attacker demands a ransom from the victim, promising — not always truthfully — to restore access to the data upon payment.
Users are shown instructions for how to pay a fee to get the decryption key. The costs can range from a few hundred dollars to thousands, payable to cybercriminals in Bitcoin.
How ransomware works
There are a number of vectors ransomware can take to access a computer. One of the most common delivery systems is phishing spam — attachments that come to the victim in an email, masquerading as a file they should trust. Once they’re downloaded and opened, they can take over the victim’s computer, especially if they have built-in social engineering tools that trick users into allowing administrative access. Some other, more aggressive forms of ransomware, like NotPetya, exploit security holes to infect computers without needing to trick users.