There are evil people in the World who need to be stopped now! (Granted, degrees of evil here, but this one is "low hanging fruit," which we can all grab):http://en.wikipedia.org/wiki/CryptoLocker
Hopefully, no one here has been a victim, but here are some things which you can do, right now, to insure that you are not a victim!
1) Install CryptoPrevent:http://www.foolishit.com/vb6-projects/cryptoprevent/
(Sorry about the URL.)
2) Use Gmail, as it filters all .exes, even if they are hidden:https://support.google.com/mail/answer/6590?hl=en
3) Use Firefox or Chrome as your default browser:http://www.mozilla.org/en-US/firefox/new/
4) Use Tails whenever possible, without Admin rights (disabled by default):https://tails.boum.org/
5) Use cold-storage full system image backups, which means disconnecting your backup device after the backup has been completed
. Good and free software here:http://clonezilla.org/
Be sure to verify your backups.
6) Use WOT ("Web of Trust"):http://www.mywot.com/
(Note that some traditional Catholic websites are "flagged." Why, I don't know!)
7) Use a good virus scanner, although, note the fact that many are failing to detect CryptoLocker until it is too late!
8) Consider using Ubuntu for your Internet surfing:http://www.ubuntu.com/
9) Do NOT visit untrustworthy Internet sites or open suspicious attachments!!! Once again, use Gmail; Google will protect you!!
10) If infected, Do NOT pay the ransom!
Instead, hit the power button on your computer and boot off an ISO:http://www.computerworld.com/s/article/9243537/Cryptolocker_How_to_avoid_getting_infected_and_what_to_do_if_you_are_