CryptoWall, the heavy-hitting file encryption malware, is back. This ransomware encrypts all the user files it can find – local hard drive, USB disk/stick, network shares, online backups – with industrial-strength encryption, and the master key is not discoverable. Bad news. A new variant is being spread via infected ads, which are being distributed by the Zedo Ad Network, and is blasting from some top-traffic web sites (including codingforums and hindustantimes). Oh yeah – this version has a valid digital signature from DigiCert, so that your computer will implicitly trust the code without squawking about it. Nasty.  Source: Barracuda Labs

Tech site Foolish IT offers a tool, CryptoPrevent, which can help stop unwanted program execution in temp folders, the recycle bin, download locations, etc., and was built to stop CryptoWall. There is a free version. It may get in the way of some desired software installations or updates, so it might require some twiddling.

Nothing, however, should take the place of a good REMOVABLE backup of your important files.