What is ransomware?
Ransomware is a kind of malware (malicious software) that criminals install on your computer so they can lock it from a remote location. Ransomware generates a pop-up window, webpage, or email warning from what looks like an official authority. It explains that your computer has been locked because of possible illegal activities on it and demands payment before you can access your files and programs again.
How do criminals install ransomware?
Ransomware is usually installed when you open a malicious email attachment or when you click a malicious link in an email message or instant message or on a social networking site or other website. Ransomware can even be installed when you visit a malicious website.
How do I avoid ransomware?
There are several free ways to help protect your computer against ransomware and other malware:
Keep all of the software on your computer up to date. Make sure automatic updating is turned on to get all the latest Microsoft security updates.
Keep your firewall turned on.
Download Microsoft Security Essentials, which is free, or use another reputable antivirus and anti-malware program. If you run Windows 8 or Windows RT, you don’t need Microsoft Security Essentials.
Scan your computer with the Microsoft Safety Scanner.
What should I do if I have ransomware on my computer?
To detect and remove ransomware and other malicious software that might be installed on your computer, run a full-system scan with an appropriate, up-to-date, security solution. The following Microsoft products can detect and remove this threat:
Microsoft Safety Scanner
Windows Defender Offline (Some ransomware will not allow you to use the products listed here, so you might have to start your computer from a Windows Defender Offline disk.)
For more information, see Help protect your PC with Microsoft Security Essentials.