Whenever people got their files encrypted - I have seen several posts here, the basic issue was that they use cracked software, key generators or various activators. Sometimes they do have a virus/malware protection but they disable it to install these. That's the bottom line. As a home user you are not protected by an Enterprise class network that ensures reasonable degree of protective measures. The only effective way to protect a user is to take every measure to stop malware being delivered to you over the network, downloads, email and to restrict your privileges. When you invite disaster, nothing can protect you.