Ransomware is a type of malware that prevents or limits users from accessing their system and/or data by encrypting it. It then forces its victims to pay a ransom in order to obtain the correct keys necessary to decrypt these files.
One common infection method is an email with a ZIP attachment or a malicious web link. For example, you receive an email with an invoice attached as invoice.zip. The ZIP attachment contains a seemingly harmless file (invoice.pdf, for example) but opening that file triggers a ransomware infection.
Effective recovery utilities are rare, due to encryption methods used by the ransomware. At best, a backup copy may be restored. At worst, ransomware variants can unknowingly damage the backed-up copies beyond anyone's ability to restore them properly.
Several suggested prevention measures are:
- Be suspicious of all attachments, even from known contacts. If you didn’t expect an attachment, proceed with extreme caution.
- Do not click links in email unless sure it is a safe and expected site. Some propagators of ransomware have started sending bogus hyperlinks instead of attachments. Hover your mouse over hyperlinks to reveal the address and compare that address with the link in the email to confirm they match.
- Backup data on your computer often. Store this backup in a separate, secure location offline or online.