There is a new generation of Ransomware out there which makes it necessary for you to back up your computer regularly irrespective if you are a home user or a business.
CryptoLocker has started to be widespread and it is very nasty. It makes all of the files on your computer (photos, decease files, documents, etc.) totally non usable. In the case of a business, this applies not only to the workstation, but also to any shared files on mapped drives to servers or other workstations. The infection can be removed readily but the damaged files are not recoverable except from a backup.
It is currently being spread by a SPAM email with a link in it. It can corrupt all of the files on your computer within minutes.
In this case prevention is better than cure; if CryptoLocker strikes then having a recent backup of the infected files is the only way to restore the file system.
Here is more detail on the CryptoLocker from McAfee:
How it works
According to the article: “The Cutwail botnet is used to send spam emails containing a link which, if clicked, will download the first stage of the infection – a small downloader program which contacts a remote server to get the malware payload.
This Upatre malware downloads and executes Gameover Zeus, which in turn downloads and installs other malware families including CryptoLocker.
After connecting to an attacker-controlled C2 server, CryptoLocker sends a phone-home message encrypted with an RSA public key embedded within the malware (see Figure 2). Only servers with the corresponding RSA private key can decrypt this message and successfully communicate with an infected system.