Just as with many other ransomware, the virus can penetrate the system not only through a Windows vulnerability, but also through the “spray-‘n’-pray” phishing attack, which involves spamming users with emails that carry a malicious attachment. The attackers can also lure a victim to click on a URL where malware will be ready to crawl into your machine.
Because ransomware targets everyday Internet users, businesses and public service providers, any individuals or organizations that needs continuous access to its systems should be especially careful what sites they visit and which attachments they open up.