Ransomware

Ransomware is a kind of cyber crime built around digital hostage-taking: the attacker gains access to a computer and then blocks the user from accessing it — usually by encrypting the user's data.

The extortion step

Once the data is locked away, the attacker blackmails the victim:

• pay up to regain access to your own data; or, in another variant,
• pay up or the attacker will publish your personal and sensitive information or photographs.

Either way, the demand is a ransom — which gives this class of malware its name.

How ransomware reaches a system

The section lists the common infection routes; each one is an ordinary-looking action a careless user might take:

• visiting a malicious or unsecure website, from which the ransomware gets downloaded;
• downloading software from doubtful repositories;
• opening email attachments sent in spam mails; and
• clicking a malicious advertisement on the Internet. …