Hi All,
I have 1 client who was suspected to be infected with a new variant of ransomware (Cryptowall). Below is an example message of the ransomware:
What happened to your files ?
All of your files were protected by a strong encryption with RSA-2048 using CryptoWall.
More information about the encryption keys using RSA-2048 can be found here: http://en.wikipedia.org/wiki/RSA_(cryptosystem)
What does this mean ?
This means that the structure and data within your files have been irrevocably changed, you will not be able to work with them, read them or see them,
it is the same thing as losing them forever, but with our help, you can restore them.
How did this happen ?
Especially for you, on our server was generated the secret key pair RSA-2048 - public and private.
All your files were encrypted with the public key, which has been transferred to your computer via the Internet.
Decrypting of your files is only possible with the help of the private key and decrypt program, which is on our secret server.
What do I do ?
Alas, if you do not take the necessary measures for the specified time then the conditions for obtaining the private key will be changed.
If you really value your data, then we suggest you do not waste valuable time searching for other solutions because they do not exist.
Additional Information:
User is running on Windows Vista, SEP 12.1 and the last AV date use to scan is on 10/7/2014 r9. It has been isolated since then. No risk is found.
User has no idea how the malware infected the machine as it does not show any signs of infection until they started to encrypt the files.
As the user is in an strict environment, we wouldn't be able to use any other tools such as SymHelp. The only way is to update SEP's definitions for this new variant so that it can remove the malware.
As such, any advice on which files to extract for Symantec signature creation/analysis? Any other recommendations would be greatly appreciated too.