I keep reading about more and more sophistication of ransomware but I don't see much about how antivirus is addressing it. I suppose the basic plan is to block the malware by signature and/or heuristics but I would like to see some specifics targeting ransomware. One strategy would be to scan the hard disk and randomly select files that are likely targets for encryption. Then open these files and perform a statistical analysis on the content. An encrypted file shows up as pure random data so it can't be hidden. Anything doing that sort of thing yet?
HitmanPro.Alert blocks professional ransomware without signatures or cloud connection. Background here: https://hitmanpro.wordpress.com/2016/02/20/are-you-up-all-night-after-getting-locky/
Malwarebytes Anti-Exploit to mention. strategies are going to fail in any way, best method is to backup regularly and to lock those backups against encrypting trojans - those are capable to infect all attached storage devices incl. NAS. at least all trojans and 0day exploits were tested against all current antivirus - so pretty pointless to count on such software.
Hitman sounds promising. Heuristic test for encryption should work. There's no way to hide the fact that a program is encrypting data. Would still like to see a robust backup strategy as well. Cloud backups are fine unless you want to use disk images. A disk image of a 2TB disk just isn't practical in the cloud. I am still looking for a NAS that can work as write once storage. My backup software could write new backup files to the NAS but then the NAS marks them as read only after some time period so ransomware can't alter them. Probably will need to go with FreeNAS or a straight up LINUX box as as NAS server since I don't see anything out there that does this off the shelf (affordable for personal use anyway)
Aside from Hitman which does indeed work, Emsisoft will also protect you, as would ERP and Appguard. As for backup, file is good imaging is better. A file backup would be a bad solution against Petya, as you would have to reinstall Windows. A disk image would just mean a restore.