Back in July, I wrote about malware designed to trick you out of personal information or money. This note is about ransomware, a new and more sophisticated type of malware that encrypts your important files and then demands hundreds of dollars for the keys to recover them.

One variant, CryptoLocker, hit over 500,000 systems in its first nine months. Your PC can be infected by opening a nasty email attachment, visiting a malicious website or downloading software from a questionable source. Or it can be loaded by other malware that may already be on your system. Once infected, you’ll get a pop-up demanding payment in order to get your files back. The payment, often in bitcoins, is usually impossible to recover.

Ransomware affects files stored on local as well as mapped network drives. This means it can encrypt files on shared drives in your home or office and on any other attached storage. Files on cloud storage services, such as Dropbox, will also be encrypted if they are mapped as folders or drives on your computer.

If you are a victim of ransomware and don’t have a current backup, it is nearly impossible to recover your files without the encryption keys. That being said, there are two drawbacks to paying the ransom; first, there is no guarantee the bandits will send you the recovery keys, and second, paying the ransom encourages this type of criminal behavior.

To avoid having ransomware trash your digital life: Don’t click on things that you’re not 100 percent sure of, show file extensions to easily identify executable files, back up your data regularly, disconnect your external drives when not in use, set your email system to deny all “.EXE” files (including inside zip files), keep your operating system and applications up to date and use a good security suite.

­— James Hyde