Security firm F-Secure has released a tool to decrypt data scrambled by the Synolocker malware – assuming you've obtained the decryption key from the crooks.
Synolocker is ransomware that attacks NAS devices made by Synology:
http://www.symantec.com/security_response/writeup.jsp?docid=2014-080708-1950-99 Those infected by the software find their data is encrypted, and receive an invitation to purchase a decryption key.
F-Secure today writes: “We believe you should never pay a ransom to online criminals":
http://www.f-secure.com/weblog/archives/00002737.html Yet, it has released a tool that puts the crims' Synolocker decryption keys to work to rescue enciphered files.
Why the seeming contradiction? Well, F-Secure's post says “the criminals behind SynoLocker make a false promise” and that “in many of the cases we have observed, the decryption process didn't actually work or the decryption key provided by the criminals was incorrect.” So, paying out is a risk, as well as encouraging this criminality, if you absolutely must get a key – and manage to do so – the new tool can help make it all work.
“Another use case for our decryption tool is a situation where a user has paid the ransom but can't use the decryption key as they have removed the SynoLocker malware from the infected device,” the company's Artturi Lehtiö writes. “Instead of reinfecting your device with the malware (which is a bad idea), you can use the key together with our script to decrypt your files.”
Those two grounds mean F-Secure feels it is worthwhile extending a helping hand to the afflicted, even though it frowns on the idea of paying ransoms.
Synolocker victims may not want to get excited about the free tool, however, as it's a python script:
https://github.com/F-Secure/Synounlocker , something the average Joe or Josephine may not find immediately usable. If that's you, here's a guide to installing Python for noobs:
https://wiki.python.org/moin/BeginnersGuide/Download , and the pycrypto toolkit:
https://pypi.python.org/pypi/pycrypto you'll need to put F-Secure's code to work:
https://github.com/F-Secure/Synounlocker(ElReg)