There is a particularly nasty piece of ransomware going round – it’s name is cryptolocker.
It is so named because it will encrypt and lock your files. When they malware (cryptolocker) has done this, the software will demand that you pay the authors money to release your files – this malware is being seen at least DAILY by our offices, it is arriving in unsolicited email and is sailing right past most antiviruses. Each time we find new samples, they are being added to the definitions by all our antivirus partners, but new samples appear daily.
In the meanwhile, we are recommending that you enforce a “group policy” to block any program running from your windows %APPDATA% folder – implementing this policy will prevent cryptolocker and other programs from executing from within certain folders on your PC – this would mean that if you receive a zipped malware which doesn’t get detected, it should fail to execute because of the policy you put in place to prevent it.
More details on the threat here:
http://www.bleepingcomputer.com/virus-removal/cryptolocker-ransomware-information
There is a link further down this article on prevention and a nice program you can run to lock-down your group-policy:
http://www.bleepingcomputer.com/virus-removal/cryptolocker-ransomware-information#prevent
Download the locking program – extract it to the desktop – run the locker and BLOCK programs running from inside your %APPDATA% folders – this *should* keep you safe. The other steps which you *MUST* do, are unsure that your JAVA, PDF Reader and Antivirus are fully up to date.
We use and recommend Ninite.com to update our Java and PDF Reader applications
Link to Java + PDF Reader Updater